Method and electronic device for performing wireless communication by using channel list

ABSTRACT

An electronic device according to one embodiment comprises: a housing; a wireless communication circuit located in the housing, and supporting a wireless protocol so as to wirelessly connect to one of a plurality of APs using the same first credential information at one time point; a processor located in the housing and electrically connected to the communication circuit; and a memory located in the housing and electrically connected to the processor. The electronic device receives, from a first AP, a list of first channels at least partially associated with at least one second AP having a coverage overlapping a coverage of the first AP and a list of second channels associated with at least one third AP that does not have a coverage overlapping the coverage of the first AP through the wireless communication circuit, wherein the first AP, the at least one second AP, and the at least one third AP use the identical first credential information.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a National Phase Entry of PCT InternationalApplication No. PCT/KR2018/002674, which was filed on Mar. 6, 2018, andclaims a priority to Korean Patent Application No. 10-2017-0029071,which was filed on Mar. 7, 2017, the contents of which are incorporatedherein by reference.

TECHNICAL FIELD

Various embodiments of the present disclosure relate to an electronicdevice that performs wireless communication.

BACKGROUND ART

Recently, electronic devices have been able to provide various functionssuch as video communication, digital media broadcasting (DMB), audio orvideo streaming, Internet, etc., as well as voice communication. Suchvarious functions provided by the electronic device are provided throughconnection with a network over a mobile communication network or throughconnection with a network via an access point (AP) that is a wirelessrepeater according to a wireless communication scheme such as WirelessFidelity (WiFi), Wireless Broadband (WiBro), etc.

When the electronic device is connected with the network through the APaccording to the wireless communication scheme such as WiFi, WiBro,etc., a coverage of the AP capable of performing wireless communicationis limited, such that even when the electronic device moves, theelectronic device may perform continuous wireless communication byperforming roaming to another AP from the currently connected AP.

DETAILED DESCRIPTION OF THE INVENTION Technical Problem

As the electronic device moves, the electronic device may performscanning to perform roaming to another AP. The electronic device may notbe aware of information about all channels associated with APs to whichthe electronic device may currently roam, and thus a time required forthe electronic device to scan an AP to which the electronic device is toroam increases, incurring additional electric current consumption.

Various embodiments of the present disclosure provide an electronicdevice to solve the foregoing or other problems.

Technical Solution

According to various embodiments of the present disclosure, anelectronic device includes a housing, a wireless communication circuitlocated inside the housing and configured to support a wireless protocolfor a wireless connection, at a time point, with one of a plurality ofaccess points (APs) that use identical first credential information, aprocessor located inside the housing and electrically connected with thewireless communication circuit, and a memory located inside the housingand electrically connected with the processor, in which the memorystores instructions that cause, when executed, the processor towirelessly connect to a first AP by using the first credentialinformation, through the wireless communication circuit, to receive alist of first channels at least partially associated with at least onesecond AP having a coverage overlapping a coverage of the first AP amongthe plurality of APs, through the wireless communication circuit, and toperform scanning with respect to the at least one second AP that usesthe first credential information by using the list of the firstchannels, through the wireless communication circuit, in which the listof the first channels includes, but not all, a plurality of channelsamong channels available from the wireless protocol.

According to various embodiments of the present disclosure, in anon-transitory computer-readable recording medium having recordedthereon a program to be executed on a computer, the program includesexecutable instructions that cause, when executed by a processor, theprocessor to wirelessly connect to a first AP by using first credentialinformation, to receive at a time point, a list of first channels atleast partially associated with at least one second AP having a coverageoverlapping a coverage of the first AP among the plurality of APs, andto perform scanning with respect to the at least one second AP that usesthe first credential information by using the list of the firstchannels, in which the list of the first channels includes, but not all,a plurality of channels among channels available from the wirelessprotocol.

According to various embodiments of the present disclosure, anelectronic device includes a housing and a wireless communicationcircuit located inside the housing and configured to support a wirelessprotocol as a first AP, in which the wireless communication circuit isconfigured to store a list of first channels associated with at leastone other AP having a coverage overlapping a coverage of the first AP,the list of the first channels including, but not all, a plurality ofchannels among channels available from the wireless protocol, towirelessly connect to an external electronic device as the first AP byusing first credential information, and to provide the list of the firstchannels to the external electronic device.

Advantageous Effects

The electronic device according to various embodiments of the presentdisclosure may receive from a wireless-communication-connected AP, achannel list associated with APs to which the electronic device maycurrently roam, and may scan an AP to which the electronic device is toroam, by using the channel list. Therefore, a time required for theelectronic device to scan an AP to which the electronic device is toroam may be reduced, and additional electric current consumption may beprevented.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates a network environment including an electronic deviceaccording to various embodiments of the present disclosure.

FIG. 2 is a block diagram of a programming module according to variousembodiments of the present disclosure.

FIG. 3 is a block diagram of an electronic device according to variousembodiments of the present disclosure.

FIG. 4 is a block diagram of an access point (AP) according to variousembodiments of the present disclosure.

FIG. 5 is a view for describing roaming of an electronic deviceaccording to a comparison example.

FIG. 6 is a flowchart illustrating a roaming method of an electronicdevice according to various embodiments of the present disclosure.

FIGS. 7A through 7C are views for describing a roaming method of anelectronic device according to various embodiments of the presentdisclosure.

FIG. 8 is a flowchart illustrating a method of updating a list ofchannels by an electronic device, according to various embodiments ofthe present disclosure.

FIG. 9 is a flowchart illustrating a method of determining whether toperform scanning for roaming by an electronic device, according tovarious embodiments of the present disclosure.

FIGS. 10A and 10B are views for describing a method of determiningwhether to perform scanning for roaming by an electronic device,according to various embodiments of the present disclosure.

FIGS. 11A and 11B are flowcharts illustrating a method of adjusting adwell time by an electronic device, according to various embodiments ofthe present disclosure.

FIGS. 12A through 12C are views for describing adjustment of a dwelltime by an electronic device, according to various embodiments of thepresent disclosure.

FIG. 13 is a flowchart illustrating a method of performing additionalscanning by an electronic device, according to various embodiments ofthe present disclosure.

FIG. 14 is a view for describing a method of performing additionalscanning by an electronic device, according to various embodiments ofthe present disclosure.

FIG. 15 is a flowchart illustrating a method of providing a list ofchannels by an AP, according to various embodiments of the presentdisclosure.

FIGS. 16A through 16D are flowcharts illustrating a method of providinga list of channels between an AP and an electronic device, according tovarious embodiments of the present disclosure.

FIGS. 17A and 17B are views for describing a roaming method of anelectronic device, according to various embodiments of the presentdisclosure.

FIGS. 18A and 18B are views for describing a roaming method of anelectronic device according to various embodiments of the presentdisclosure.

FIGS. 19A and 19B are flowcharts illustrating a roaming method of anelectronic device, according to various embodiments of the presentdisclosure.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, various embodiments of the present disclosure will bedisclosed with reference to the accompanying drawings. However,embodiments and terms used therein are not intended to limit the presentdisclosure to particular embodiments, and it should be construed asincluding various modifications, equivalents, and/or alternativesaccording to the embodiments of the present disclosure. With regard tothe description of the drawings, similar reference numerals may be usedto refer to similar or related elements. It is to be understood that asingular form of a noun corresponding to an item may include one or moreof the things, unless the relevant context clearly indicates otherwise.In the present disclosure, an expression such as “A or B,” “at least oneof A or/and B,” or “one or more of A or/and B” may include all possiblecombinations of together listed items. Expressions such as “first,”“second,” “primarily,” or “secondary,” used herein may represent variouselements regardless of order and/or importance and do not limitcorresponding elements. When it is described that an element (such as afirst element) is “operatively or communicatively coupled with/to” or“connected” to another element (such as a second element), the elementcan be directly connected to the other element or can be connected tothe other element through another element (e.g., a third element).

An expression “configured (or designated) to” used in the presentdisclosure may be replaced with, for example, “suitable for,” “havingthe capacity to,” “adapted to,” “made to,” “capable of,” or “designedto” according to a situation. Alternatively, in some situation, anexpression “apparatus configured to” may mean that the apparatus “can”operate together with another apparatus or component. For example, aphrase “a processor configured (or designated) to perform A, B, and C”may be a dedicated processor (e.g., an embedded processor) forperforming a corresponding operation or a generic-purpose processor(such as a central processing unit (CPU) or an application processor)that can perform a corresponding operation by executing at least onesoftware program stored at a memory device. A term “configured to (orset)” does not always mean only “specifically designed to” by hardware.

An electronic device according to various embodiments of the presentdisclosure may include at least one of, for example, a smartphone, atablet personal computer (PC), a mobile phone, a video phone, anelectronic-book (e-book) reader, a desktop PC, a laptop PC, a netbookcomputer, a workstation, a server, a personal digital assistant (PDA), aportable multimedia player (PMP), an MP3 player, a mobile medicalequipment, a camera, or a wearable device. Examples of the wearabledevice may include at least one of an accessory type (e.g., a watch, aring, a bracelet, an anklet, a necklace, glasses, contact lenses,head-mounted device (HMD), etc.), a fabric or cloth-integrated type(e.g., electronic clothing, etc.), a body-attached type (e.g., a skinpad, a tattoo, etc.), a body implantable circuit, or the like. In someembodiments, the electronic device may include, for example, at leastone of a television (TV), a digital video disk (DVD) player, audioequipment, a refrigerator, an air conditioner, a vacuum cleaner, anoven, a microwave oven, a laundry machine, an air cleaner, a set-topbox, a home automation control panel, a security control panel, a mediabox (e.g., Samsung HomeSync™, Apple TV™, or Google TV™), a game console(e.g., Xbox™ or PlayStation™), an electronic dictionary, an electronickey, a camcorder, or an electronic frame.

In other embodiments, the electronic device may include at least one ofvarious medical equipment (e.g., various portable medical measurementdevices (a blood glucose meter, a heart rate measuring device, a bloodpressure measuring device, a body temperature measuring device, etc.),magnetic resonance angiography (MRA), magnetic resonance imaging (MRI),computed tomography (CT), an imaging device, or an ultrasonic device), anavigation system, a global navigation satellite system (GNSS), an eventdata recorder (EDR), a flight data recorder (FDR), a vehicleinfotainment device, electronic equipment for ships (e.g., a navigationsystem and gyro compass for ships), avionics, a security device, avehicle head unit, an industrial or home robot, an automatic teller'smachine (ATM), a point of sales (POS), Internet of things (e.g.,electric bulbs, various sensors, electricity or gas meters, sprinklerdevices, fire alarm devices, thermostats, streetlights, toasters,exercise machines, hot-water tanks, heaters, boilers, and so forth).According to some embodiments, the electronic device may include a partof a furniture, building/structure or a part of a vehicle, an electronicboard, an electronic signature receiving device, a projector, andvarious measuring instruments (e.g., a water, electricity, gas, electricwave measuring device, etc.). According to various embodiments, theelectronic device may be flexible or may be a combination of two or moreof the above-described various devices. According to an embodiment ofthe disclosure, the electronic devices are not limited to thosedescribed above. Herein, the term “user” used in various embodiments ofthe present disclosure may refer to a person who uses the electronicdevice or a device using the electronic device (e.g., an artificialintelligence electronic device).

Referring to FIG. 1, an electronic device 101 in a network environment100 according to various embodiments of the present disclosure isdisclosed. The electronic device 101 may include a bus 110, a processor120, a memory 130, an input/output (I/O) interface 150, a display 160,and a communication interface 170. According to some embodiments, theelectronic device 101 may omit at least one of the foregoing elements ormay further include other elements. The bus 110 may include a circuitfor connecting, e.g., the elements 110 to 170 and deliveringcommunication (e.g., a control message or data) between the elements 110to 170. The processor 120 may include one or more of a centralprocessing unit (CPU), an application processor (AP), and acommunication processor (CP). The processor 120 may perform operationsor data processing for control and/or communication of, for example, atleast one other elements of the electronic device 101.

The memory 130 may include a volatile and/or nonvolatile memory. Thememory 130 may store, for example, instructions or data associated withat least one other elements of the electronic device 101. According toan embodiment, the memory 130 may store software and/or a program 140.The program 140 may include at least one of, for example, a kernel 141,middleware 143, an application programming interface (API) 145, and/oran application program (or “application”) 147, and the like. At leastsome of the kernel 141, the middleware 143, and the API 145 may bereferred to as an operating system (OS). The kernel 141 may control ormanage, for example, system resources (e.g., the bus 110, the processor120, the memory 130, etc.) used to execute operations or functionsimplemented in other programs (e.g., the middleware 143, the API 145, orthe application program 147). The kernel 141 provides an interfacethrough which the middleware 143, the API 145, or the applicationprogram 147 accesses separate components of the electronic device 101 tocontrol or manage the system resources.

The middleware 143 may work as an intermediary for allowing, forexample, the API 145 or the application program 147 to exchange data incommunication with the kernel 141. In addition, the middleware 143 mayprocess one or more task requests received from the application program147 based on priorities. For example, the middleware 143 may give apriority for using a system resource (e.g., the bus 110, the processor120, the memory 130, etc.) of the electronic device 101 to at least oneof the application programs 147, and may process the one or more taskrequests. The API 145 is an interface used for the application 147 tocontrol a function provided by the kernel 141 or the middleware 143, andmay include, for example, at least one interface or function (e.g., aninstruction) for file control, window control, image processing orcharacter control. The I/O interface 150 may deliver, for example, aninstruction or data input from a user or another external device toother component(s) of the electronic device 101, or output aninstruction or data received from other component(s) of the electronicdevice 101 to a user or another external device.

The display 160 may include, for example, a liquid crystal display(LCD), a light emitting diode (LED) display, an organic light emittingdiode (OLED) display, a microelectromechanical system (MEMS) display, oran electronic paper display. The display 160 may, for example, displayvarious contents (e.g., a text, an image, video, an icon, and/or asymbol, etc.) to users. The display 160 may include a touch screen, andreceives a touch, a gesture, proximity, or a hovering input, forexample, by using an electronic pen or a part of a body of a user. Thecommunication interface 170 establishes communication between theelectronic device 101 and an external device (e.g., the vehicle device102, the electronic device 104, or the server 106). For example, thecommunication interface 170 may be connected to a network 162 through awireless communication or wired communication to communicate with anexternal device (e.g., the second external electronic device 104 or theserver 106).

The wireless communication may include cellular communication using atleast one of Long-Term Evolution (LTE), LTE-Advanced (LTE-A), CodeDivision Multiple Access (CDMA), Wideband CDMA (WCDMA), a UniversalMobile Telecommunication System (UMTS), Wireless Broadband (WiBro), orGlobal System for Mobile Communications (GSM)). According to anembodiment, the wireless communication may include at least one ofWireless Fidelity (WiFi), Light Fidelity (LiFi), Bluetooth, BluetoothLow Energy (BLE), Zigbee, near field communication (NFC), magneticsecure transmission (MST), radio frequency (RF), and a body area network(BAN), as illustrated as an element 164 in FIG. 1. According to anembodiment, the wireless communication may include a global navigationsatellite system (GNSS). The GNSS may include, for example, at least oneof a global positioning system (GPS), a global navigation satellitesystem (Glonass), a Beidou navigation satellite system (“Beidou”), orGalileo, the European global satellite-based navigation system.Hereinbelow, “GPS” may be used interchangeably with “GNSS”. The wiredcommunication may include, for example, at least one of a universalserial bus (USB), a high definition multimedia interface (HDMI),Recommended Standard 232 (RS-232), power line communication, a plain oldtelephone service (POTS), or the like. The network 162 may include atelecommunications network, for example, at least one of a computernetwork (e.g., a local area network (LAN) or a wide area network (WAN)),Internet, and a telephone network.

Each of the first external electronic device 102 and the second externalelectronic device 104 may be a device of the same type as or a differenttype than the electronic device 101. According to various embodiments ofthe present disclosure, some or all of operations performed by theelectronic device 101 may be performed in another electronic device or aplurality of electronic devices (e.g., the electronic device 102 or 104,or the server 106). According to an embodiment of the presentdisclosure, when the electronic device 101 has to perform a function ora service automatically or at a request, the electronic device 101 mayrequest another device (e.g., the electronic devices 102 or 104 or theserver 106) to perform at least some functions associated with thefunction or the service instead of or in addition to executing thefunction or the service. The another electronic device (e.g., theelectronic device 102 or 104 or the server 106) may execute therequested function or additional function and deliver the executionresult to the electronic device 101. The electronic device 101 may thenprocess or further process the received result to provide the requestedfunction or service. To that end, a cloud computing, distributedcomputing, or client-server computing technology may be used, forexample.

According to various embodiments of the present disclosure, elementsincluded in the electronic device 101 illustrated in FIG. 1 may bearranged inside a housing of the electronic device 101. The elementsincluded in the electronic device 101 may be electrically connected withone another.

According to various embodiments of the present disclosure, a wirelesscommunication circuit (e.g., the communication interface 170) maysupport a wireless protocol so as to be wirelessly connected to one of aplurality of APs using identical credential information. The wirelessprotocol may include protocols based on various communication schemes,e.g., a WiFi protocol, etc.

According to various embodiments of the present disclosure, thecredential information may be used for wireless communication connectionor AP scanning and may include at least one of security information suchas a service set identifier (SSID), a password, etc.

According to various embodiments of the present disclosure, the memory130 may include instructions for operating the processor 120. Forexample, the memory 130 may include instructions for causing theprocessor 120 to control other elements of the electronic device 101 andto interwork with the other electronic device 120 or 104 or the server106. The processor 120 may control other elements of the electronicdevice 101 and interwork with the other electronic device 102 or 104 orthe server 106 based on the instructions stored in the memory 130.Hereinafter, operations of the electronic device 101 will be describedbased on each element of the electronic device 101. Instructions forcausing each element of the electronic device 101 to perform theoperations may be stored in the memory 130.

According to various embodiments of the present disclosure, theprocessor 120 may be a general-purpose processor such as a CPU, an AP, aCP, or etc., or a processor embedded in a particular element forperforming various embodiments of the present disclosure.

According to various embodiments of the present disclosure, theprocessor 120 may wirelessly connect to a first AP using credentialinformation through the wireless communication circuit included in theelectronic device 101. For example, the processor 120 may performscanning with respect to at least one accessible AP to perform awireless communication connection. According to various embodiments ofthe present disclosure, an AP may be a device for connecting electronicdevices that performs wireless communication to a wired device orrelaying communication between the electronic devices. The processor 120may perform scanning with respect to the at least one AP by using atleast a part of the credential information. For example, the processor120 may use at least a part of the credential information to performscanning with respect to at least one AP using the identical credentialinformation.

The processor 120 may send a probe request to at least one channelthrough the wireless communication circuit and receive a probe responsesent from an AP of the same channel in response to the sent proberequest, thus performing scanning with respect to at least oneconnectable AP. The processor 120 may select the first AP to be accessedfor wireless communication connection through scanning based on a resultof the scanning and access the selected first AP by using the credentialinformation.

According to various embodiments of the present disclosure, theprocessor 120 may receive a list of first channels at least partiallyassociated with at least one second AP having a coverage overlapping acoverage of the first AP among a plurality of APs using identicalcredential information through the wireless communication circuit. Forexample, the processor 120 may receive the list of the first channelsfrom the first AP. The processor 120 may receive the list of the firstchannels from another electronic device or a server that manages theplurality of APs. The list of the first channels may include, but notall, a plurality of channels among available channels from a wirelessprotocol supported by the wireless communication circuit. For example,the list of the first channels may be associated with at least onesecond AP having the coverage overlapping that of the first AP, and mayinclude, but not all, the plurality of channels among available channelsfrom the wireless protocol.

According to various embodiments of the present disclosure, theprocessor 120 may receive information about the first channels at leastpartially associated with the at least one second AP. The processor 120may generate the list of the first channels by using the receivedinformation about the first channels at least partially associated withthe at least one second AP. The processor 120 may receive theinformation about the at least one second AP. The processor 120 mayfurther use the received information about the at least one second APduring generation of the list of the first channels. For example, theinformation about the at least one second AP may include stateinformation regarding the at least one second AP, location informationregarding the at least one second AP, address information regarding theat least one second AP. However, this is merely an example for adescription, and the present disclosure is not limited to the example,such that various information associated with the at least one second APmay be used to generate the list of the first channels.

According to various embodiments of the present disclosure, theprocessor 120 may delete the received or generated list of the firstchannels after an elapse of a designated time.

According to various embodiments of the present disclosure, theplurality of APs may have a coverage allowing wireless communicationconnection, and may perform wireless communication connection withelectronic devices located in the coverage. The coverage of theplurality of APs is limited, such that as the electronic device 101located in the coverage moves out of the coverage, wirelesscommunication connection between the plurality of APs and the electronicdevice 101 may be released. To perform continuous wirelesscommunication, the electronic device 101 may scan another AP connectableto perform wireless communication and may perform roaming by performingwireless communication connection with an AP found through scanning.

For example, the roaming performed by the electronic device 101 mayinclude a series of operations of the electronic device 101 to performwireless communication connection with at least one other AP, when,during communication of the electronic device 101 with at least one APconnected thereto, a condition of communication with the connected atleast one AP is degraded because the electronic device 101 becomesdistant from the connected at least one AP due to movement of theelectronic device 101 or because of other reasons. To perform roaming,the electronic device 101 may receive and store the list of the firstchannels. The electronic device 101 may receive, for example, theinformation about the first channels and generate the list of the firstchannels by using the received information about the first channels.

According to various embodiments of the present disclosure, theprocessor 120 may perform scanning with respect to the at least onesecond AP that uses the credential information by using the list of thefirst channels through the wireless communication circuit. For example,the processor 120 may send a probe request through the first channels byusing the information about the first channels included in the list ofthe first channels, and receive a probe response, thereby performingscanning with respect to the at least one second AP.

According to various embodiments of the present disclosure, theprocessor 120 may obtain a channel utilization (CU) value associatedwith each of the at least one second AP from the at least one second AP.The processor 120 may compare the obtained CU value associated with eachof the at least one second AP with a designated threshold value. Theprocessor 120 may select at least one AP for which scanning is to beperformed, based on a result of the comparison. The processor 120 mayperform scanning with respect to the selected at least one AP throughthe wireless communication circuit. The processor 120 may not performscanning with respect to an AP of a channel currently having a high CUvalue, thus reducing a time required for scanning performed for roaming.The processor 120 may not perform scanning through all of availablechannels, thus reducing a time required for roaming. Inconveniencecaused by data interruption that may occur due to roaming of theelectronic device 101 may be addressed.

According to various embodiments of the present disclosure, theprocessor 120 may perform scanning with respect to the at least onesecond AP after detecting that a wireless connection for the first APfails to satisfy a designated threshold condition. For example, theprocessor 120 may perform scanning with respect to the at least onesecond AP through the wireless communication circuit when an RSSI valuefor the first AP is less than or equal to a designated first thresholdvalue. In another example, the processor 120 may perform scanning withrespect to the at least one second AP through the wireless communicationcircuit when an RSSI value for the first AP exceeds the designated firstthreshold value and is less than or equal to a designated secondthreshold value, and a CU value for the first AP is greater than orequal to a designated third threshold value.

According to various embodiments of the present disclosure, a CU valuemay be calculated by an AP using:Channel Utilization=Integer((channel busy time/(dot11 ChannelUtilization Beacon Intervals×dot11 Beacon Period×1024))×255)  [Equation1]

In Equation (1), the CU value is a value quantifying how busy a channelis, and based on the CU value, how much free time there is in a channelmay be calculated. For Equation (1) according to various embodiments ofthe present disclosure, the 802.11 standard document (Institute ofElectrical and Electronics Engineers (IEEE) Standard 802.11TM-2012) maybe referred to. According to various embodiments of the presentdisclosure, the processor 120 may use a CU value calculated by an AP,and an extra throughput possible in the AP may be predicted using abandwidth, a modulation and coding scheme (MCS) index, and/or an RSSIvalue and whether to perform scanning for roaming may be determinedbased on the extra throughput. For example, the processor 120 maycalculate a roaming trigger score as shown in Equation (2), and scanningfor roaming may be performed when the roaming trigger score decreases toa designated threshold value or less instantly or during a designatedperiod.Roaming Trigger Score=(1−CU/255)×(MAX TP (throuput) with MCS Index andBandwidth)  [Equation 2]

According to various embodiments of the present disclosure, theprocessor 120 may perform scanning with respect to the at least onesecond AP and then perform a wireless connection with one of the atleast one second AP by using the credential information through thewireless communication circuit. For example, the processor 120 mayobtain at least one of an RSSI value or a CU value for each of the atleast one second AP. The processor 120 may obtain an RSSI value for theat least one second AP through signals (e.g., a probe request, a proberesponse, etc.) transmitted and received to and from the at least onesecond AP during scanning with respect to the at least one second AP.The processor 120 may obtain a CU value for the at least one second APfrom the at least one second AP during scanning with respect to the atleast one second AP.

According to various embodiments of the present disclosure, theprocessor 120 may select an AP that is to bewireless-communication-connected from among the at least one second AP,by using at least one of the obtained RSSI value or CU value for the atleast one second AP. The processor 120 may perform the wirelesscommunication connection with the AP selected from among the at leastone second AP.

According to various embodiments of the present disclosure, theprocessor 120 may receive a list of second channels associated with atleast one third AP that does not have a coverage overlapping that of thefirst AP among the plurality of APs through the wireless communicationcircuit. The processor 120 may receive the list of the second channelsassociated with the at least one third AP determined to be connectablebased on a location of the first AP, even when the at least one third APdoes not have the coverage overlapping that of thewireless-communication-connected first AP. For example, the processor120 may receive the list of the second channels associated with the atleast one third AP located within a designated distance from thelocation of the first AP, even when the at least one third AP does nothave the coverage overlapping that of the first AP. In spite of APsusing identical credential information, channels associated with an APdetermined that roaming to the AP is not physically possible based onthe location of the first AP may not be included in the list of thesecond channels.

For example, the list of the second channels may include, but not all, aplurality of channels among available channels from a wireless protocolsupported by the wireless communication circuit. For example, the listof the second channels may be associated with the at least one third APhaving the coverage overlapping that of the first AP, and may include,but not all, the plurality of channels among available channels from thewireless protocol.

According to various embodiments of the present disclosure, theprocessor 120 may perform scanning with respect to the at least onethird AP that uses the credential information by using the list of thesecond channels through the wireless communication circuit. For example,the processor 120 may perform scanning with respect to the at least onesecond AP by using the list of the first channels, and may furtherperform scanning with respect to the at least one third AP by using thelist of the second channels.

According to various embodiments of the present disclosure, theprocessor 120 may perform scanning with respect to the at least onesecond AP and the at least one third AP and then perform a wirelessconnection with one of the at least one second AP and the at least onethird AP by using the credential information through the wirelesscommunication circuit.

According to various embodiments of the present disclosure, theprocessor 120 may receive the list of the third channels associated withat least one fourth AP having a coverage overlapping that of an APwirelessly connected after performing the scanning among the pluralityof APs, through the wireless communication circuit. The processor 120may update the list of the first channels associated with the receivedfirst AP by using the received list of the third channels. The processor120 may perform a new wireless communication connection with the AP, andupdate the list of the first channels, which is a list of channels usedfor existing roaming, based on the currently connected AP by using thelist of the third channels, as the wireless connection with the first APis released. For example, the processor 120 may compare the list of thefirst channels with the list of the third channels, identify channelsthat are not included in the list of the first channels from among thethird channels included in the list of the third channels, and add theidentified channels to the list of the first channels, thereby updatingthe list of the first channels.

According to various embodiments of the present disclosure, theprocessor 120 may adjust a dwell time for at least one channel amongchannels associated with at least one AP for which scanning is to beperformed. The dwell time may indicate a designated time waited fortransmission of a probe request to at least one channel and reception ofa probe response transmitted from an AP of the same channel in responseto the transmitted probe request when scanning is performed.

According to various embodiments of the present disclosure, theprocessor 120 may adjust the dwell time according to a complexity of achannel. For example, the processor 120 may determine complexities offirst channels associated with the at least one second AP. The processor120 may determine the complexities of the first channels by identifyingthe amount of use of the first channels, a time for which the firstchannels are occupied, etc. The processor 120 may adjust a dwell timefor at least one channel determined to have a channel complexity greaterthan or equal to a designated threshold value among the first channels,based on a result of the complexity determination with respect to thefirst channels.

According to various embodiments of the present disclosure, theprocessor 120 may adjust the dwell time according to the number ofidentified APs for which scanning is to be performed using a list ofchannels or a channel list. For example, when the number of at least onesecond APs identified using the list of the first channels is less thanor greater than a designated value, the processor 120 may increase adwell time for channels associated with the at least one second AP.

According to various embodiments of the present disclosure, theprocessor 120 may determine whether to perform additional scanningaccording to a complexity of a channel. For example, the processor 120may determine the complexities of the first channels associated with theat least one second AP. After completing scanning for the firstchannels, the processor 120 may perform additional scanning for at leastone channel determined to have a channel complexity greater than orequal to a designated threshold value among the first channels, based ona result of the complexity determination with respect to the firstchannels.

FIG. 2 is a block diagram of an electronic device 201 according tovarious embodiments of the present disclosure. The electronic device 201may form the entire electronic device 101 illustrated in FIG. 1 or apart of the electronic device 101 illustrated in FIG. 1. The electronicdevice 201 may include one or more processors (e.g., applicationprocessors (APs)) 210, a communication module 220, a subscriberidentification module (SIM) 224, a memory 230, a sensor module 240, aninput device 250, a display 260, an interface 270, an audio module 280,a camera module 291, a power management module 295, a battery 296, anindicator 297, and a motor 298. The processor 210 controls multiplehardware or software components connected to the processor 210 bydriving an operating system (OS) or an application program, and performsprocessing and operations with respect to various data. The processor210 may be implemented with, for example, a system on chip (SoC).According to an embodiment of the present disclosure, the server 210 mayinclude a graphic processing unit (GPU) and/or an image signalprocessor. The processor 210 may include at least some of the elementsillustrated in FIG. 2 (e.g., the cellular module 221). The processor 210loads an instruction or data received from at least one of otherelements (e.g., a non-volatile memory) into a volatile memory to processthe instruction or data, and stores result data in the non-volatilememory.

The communication module 220 may have a configuration that is the sameas or similar to the communication interface 170. The communicationmodule 220 may include, for example, the cellular module 221, a WiFimodule 223, a Bluetooth (BT) module 225, a GNSS module 227, an NFCmodule 228, and a radio frequency (RF) module 229. The cellular module221 may provide, for example, a voice call, a video call, a textservice, or an Internet service over a communication network. Accordingto an embodiment of the present disclosure, the cellular module 221 mayidentify and authenticate the electronic device 201 in a communicationnetwork by using the SIM 224 (e.g., a SIM card). According to anembodiment of the present disclosure, the cellular module 221 mayperform at least one of functions that may be provided by the processor210. According to an embodiment of the present disclosure, the cellularmodule 221 may include a communication processor (CP). According to anembodiment of the present disclosure, at least some (e.g., two or more)of the cellular module 221, the WiFi module 223, the BT module 225, theGNSS module 227, or the NFC module 228 may be included in one integratedchip (IC) or IC package. The RF module 229 may, for example, transmitand receive a communication signal (e.g., an RF signal). The RF module229 may include a transceiver, a power amp module (PAM), a frequencyfilter, a low noise amplifier (LNA), or an antenna. According to anotherembodiment of the present disclosure, at least one of the cellularmodule 221, the WiFi module 223, the BT module 225, the GNSS module 227,or the NFC module 228 may transmit and receive an RF signal through theseparate RF module. The SIM 224 may, for example, include a cardincluding a SIM or an embedded SIM, and may include uniqueidentification information (e.g., an integrated circuit card identifier(ICCID) or subscriber information (e.g., an international mobilesubscriber identity (IMSI)).

The memory 230 (e.g., the memory 130) may, for example, include aninternal memory 232 and/or an external memory 234. The internal memory232 may, for example, include at least one of a volatile memory (e.g.,dynamic random access memory (DRAM), static RAM (SRAM), synchronousdynamic RAM (SDRAM), etc.), and a non-volatile memory (e.g., one timeprogrammable read only memory (OTPROM), programmable ROM (PROM),erasable and programmable ROM (EPROM), electrically erasable andprogrammable ROM (EEPROM), etc.), mask ROM, flash ROM, a flash memory,and a solid state drive (SSD). The external memory 234 may furtherinclude flash drive, for example, compact flash (CF), secure digital(SD), micro-SD, mini-SD, extreme Digital (xD), a multi-media card (MMC),or a memory stick. The external memory 234 may be functionally orphysically connected with the electronic device 201 through variousinterfaces.

The sensor module 240 measures physical quantity or senses an operationstate of the electronic device 201 to convert the measured or sensedinformation into an electric signal. The sensor module 240 may, forexample, include at least one of a gesture sensor 240A, a gyro sensor240B, a pressure sensor 240C, a magnetic sensor 240D, an accelerationsensor 240E, a grip sensor 240F, a proximity sensor 240G, a color sensor240H (e.g., RGB sensor), a biometric sensor 240I, a temperature/humiditysensor 240J, an illumination sensor 240K, and a ultraviolet (UV) sensor240M. Additionally or alternatively, the sensor module 240 may includean E-nose sensor (not shown), an electromyography (EMG) sensor (notshown), an electroencephalogram (EEG) sensor (not shown), anelectrocardiogram (ECG) sensor (not shown), an infrared (IR) sensor, aniris sensor, and/or a fingerprint sensor. The sensor module 240 mayfurther include a control circuit for controlling at least one sensorincluded therein. In some embodiment of the present disclosure, theelectronic device 201 may further include a processor configured tocontrol the sensor module 240 as part of or separately from theprocessor 210, to control the sensor module 240 during a sleep state ofthe processor 210.

The input device 250 may include, for example, a touch panel 252, a(digital) pen sensor 254, a key 256, or an ultrasonic input device 258.The touch panel 252 may use at least one of a capacitive type, aresistive type, an IR type, or an ultrasonic type. The touch panel 252may further include a control circuit. The touch panel 252 may furtherinclude a tactile layer to provide tactile reaction to the user. The(digital) pen sensor 254 may include a recognition sheet which is a partof the touch panel 252 or a separate recognition sheet. The key 256 mayalso include a physical button, an optical key, or a keypad. Theultrasonic input device 258 senses ultrasonic waves generated by aninput means through a microphone (e.g., the microphone 288) and checksdata corresponding to the sensed ultrasonic waves.

The display 260 (e.g., the display 160) may include a panel 262, ahologram device 264, a projector 266, and/or a control circuit forcontrolling them. The panel 262 may be implemented to be flexible,transparent, or wearable. The panel 262 may be configured with the touchpanel 252 in one module. According to an embodiment of the presentdisclosure, the panel 262 may include a pressure sensor (or a “forcesensor”) capable of measuring a strength of a pressure by a user'stouch. The pressure sensor may be implemented integrally with the touchpanel 252 or may be implemented as one or more sensors separate from thetouch panel 252. The hologram device 264 may show a stereoscopic imagein the air by using interference of light. The projector 266 may displayan image onto a screen through projection of light. The screen may bepositioned inside or outside the electronic device 201. According to anembodiment, the interface 270 may include a high-definition multimediainterface (HDMI) 272, a universal serial bus (USB) 274, an opticalcommunication 276, or a D-subminiature 278. The interface 270 may beincluded in the communication interface 170 illustrated in FIG. 1.Additionally or alternatively, the interface 270 may include, forexample, an MHL interface, an SD card/MMC interface, or an IrDA standardinterface.

The audio module 280 may bi-directionally convert sound and an electricsignal. At least one element of the audio module 280 may be included inthe I/O interface 145 illustrated in FIG. 1. The audio module 280 mayprocess sound information input or output through the speaker 282, thereceiver 284, the earphone 286, or the microphone 288. The camera module291 may be, for example, a device capable of capturing a still image ora moving image, and according to an embodiment, may include one or moreimage sensors (e.g., a front sensor or a rear sensor), a lens, an imagesignal processor (ISP), or a flash (e.g., an LED, a xenon lamp, etc.).The power management module 295 may manage power of the electronicdevice 201. According to an embodiment of the present disclosure, thepower management module 295 may include a power management integratedcircuit (PMIC), a charger IC, or a battery fuel gauge. The PMIC may havea wired and/or wireless charging scheme. The wireless charging schememay include a magnetic-resonance type, a magnetic induction type, and anelectromagnetic type, and may further include an additional circuit forwireless charging, for example, a coil loop, a resonance circuit, arectifier, etc. The battery gauge may measure the remaining capacity ofthe battery 296 or the voltage, current, or temperature of the battery296 during charging. The battery 296 may include, for example, arechargeable battery and/or a solar battery.

The indicator 297 displays a particular state, for example, a bootingstate, a message state, or a charging state, of the electronic device201 or a part thereof (e.g., the processor 210). The motor 298 mayconvert an electric signal into mechanical vibration or generatesvibration or a haptic effect. The electronic device 201 may include adevice for supporting the mobile TV (e.g., a GPU) to process media dataaccording to a standard such as digital multimedia broadcasting (DMB),digital video broadcasting (DVB), or mediaFlo™. Each of the foregoingelements described herein may be configured with one or more components,names of which may vary with a type of the electronic device. In variousembodiments of the present disclosure, some components of the electronicdevice (e.g., the electronic device 201) may be omitted or may furtherinclude other elements, and some of the components may be coupled toform one entity and identically perform functions of the componentsbefore being coupled.

FIG. 3 is a block diagram of a programming module according to variousembodiments of the present disclosure. According to an embodiment of thepresent disclosure, a programming module 310 (e.g., the program 140) mayinclude an OS for controlling resources associated with an electronicdevice (e.g., the electronic device 101) and/or various applications(e.g., the application program 147) executed on the OS. The OS mayinclude Android™, iOS™, Windows™, Symbian™, Tizen™, or Bada™. Referringto FIG. 3, the programming module 310 may include a kernel 320 (e.g.,the kernel 141), middleware 330 (e.g., the middleware 143), anapplication programming interface (API) 360 (e.g., the API 145), and/oran application 370 (e.g., the application program 147). At least a partof the programming module 310 may be preloaded on an electronic deviceor may be downloaded from an external device (e.g., the electronicdevice 102 or 104, or the server 106).

The kernel 320 may include a system resource manager 321 and/or a devicedriver 323. The system resource manager 321 may perform control,allocation, retrieval of system resources, and so forth. According to anembodiment of the present disclosure, the system resource manager 321may include a process management unit, a memory management unit, or afile system management unit. The device driver 323 may include, forexample, a display driver, a camera driver, a Bluetooth driver, a sharedmemory driver, a USB driver, a keypad driver, a WiFi driver, an audiodriver, or an inter-process communication (IPC) driver. The middleware330 may include provide functions that the application 370 commonlyrequires or provide various functions to the application 370 through theAPI 360 to allow the application 370 to use a limited system resource inan electronic device. According to an embodiment, the middleware 330 mayinclude at least one of a runtime library 335, an application manager341, a window manager 342, a multimedia manager 343, a resource manager344, a power manager 345, a database manager 346, a package manager 347,a connectivity manager 348, a notification manager 349, a locationmanager 350, a graphic manager 351, and a security manager 352.

The runtime library 335 may include a library module that a compileruses to add a new function through a programming language while theapplication 370 is executed. The runtime library 335 performsinput/output management, memory management, or calculation functionprocessing. The application manager 341 may manage a life cycle of theapplications 370. The window manager 342 may manage a graphic userinterface (GUI) resource used in a screen. The multimedia manager 343may recognize a format necessary for playing media files and performencoding or decoding on a media file by using a codec appropriate for acorresponding format. The resource manager 344 may manage a source codeor a memory space of the applications 370. The power manager 345 maymanage a battery or power and provide power information necessary for anoperation of the electronic device. According to an embodiment, thepower manager 345 may operate with basic input/output system (BIOS). Thedatabase manager 346 may generate, search or change a database used forat least one application among the applications 370. The package manager347 may manage the installation or update of an application distributedin a package file format.

The connectivity manager 348 may manage a wireless connection. Thenotification manager 349 may provide an event, e.g., an arrivingmessage, an appointment, proximity notification, etc. The locationmanager 350 may manage location information about an electronic device.The graphic manager 351 may manage, for example, a graphic effect to beprovided to a user or a user interface relating thereto. The securitymanager 352 may provide, for example, system security or userauthentication. According to an embodiment of the present disclosure,the middleware 330 may further include a telephony manager for managinga voice or video call function of the electronic device or a middlewaremodule forming a combination of functions of the above-describedcomponents. According to an embodiment of the present disclosure, themiddleware 330 may provide a module specified for each type of an OS.Additionally, the middleware 330 may delete some of existing elements oradd new elements dynamically. The API 360 may be provided as a set ofAPI programming functions with a different configuration according tothe OS. In the case of Android or iOS, for example, one API set may beprovided by each platform, and in the case of Tizen, two or more APIsets may be provided.

The application 370 may include one or more applications capable ofproviding a function, for example, a home application 371, a dialerapplication 372, a short messaging service/multimedia messaging service(SMS/MMS) application 373, an instant message (IM) application 374, abrowser application 375, a camera application 376, an alarm application377, a contact application 378, a voice dial application 379, an e-mailapplication 380, a calendar application 381, a media player application382, an album application 383, a clock application 384, a health careapplication (e.g., an application for measuring an exercise amount, ablood sugar, etc.), or an environment information providing application(e.g., an application for providing air pressure, humidity, ortemperature information or the like). According to an embodiment, theapplication 370 may include an information exchange applicationsupporting information exchange between the electronic device and anexternal electronic device. The information exchange application mayinclude, for example, a notification relay application for transferringspecific information to the external electronic device or a devicemanagement application for managing the external electronic device. Forexample, the notification relay application may deliver notificationinformation generated in another application of the electronic device toan external electronic device or may receive notification informationfrom the external electronic device and provide the notificationinformation to the user. The device management application may manage(e.g., install, remove, or update) a function (e.g., turn on/turn off ofan external electronic device itself (or a part thereof) or control ofbrightness (or resolution) of a display) of an external devicecommunicating with the electronic device, a service provided by anapplication operating in an external electronic device or provided bythe external electronic device (e.g., a call service or a messageservice). According to an embodiment, the application 370 may include anapplication (e.g., device health care application of mobile medicalequipment) designated according to an attribute of the externalelectronic device. According to an embodiment, the application 370 mayinclude an application received from the external electronic device. Theat least a part of the programming module 310 may be implemented (e.g.,executed) by software, firmware, hardware (e.g., the processor 210), ora combination of two or more of them, and may include, for example,modules, programs, routines, sets of instructions, or processes forperforming one or more functions.

FIG. 4 is a block diagram of an AP according to various embodiments ofthe present disclosure.

According to various embodiments of the present disclosure, an AP 400may include a wireless communication circuit 410 and a memory 420 thatare located in a housing thereof.

According to various embodiments of the present disclosure, the AP 400may be a device for connecting various electronic devices that performswireless communication to a wired device or relaying communicationbetween the wireless communication electronic devices. Although notshown, the AP 400 may include a slot connectable with a wiredcommunication cable and may be connected to a wired communicationnetwork through the wired communication cable and transmit and receivedata to and from a server or an external another electronic devicethrough the connected wired communication network. Although not shown,the AP 400 may include at least one of the elements included in theelectronic device 101 illustrated in FIG. 1 and the electronic device201 illustrated in FIG. 2.

According to various embodiments of the present disclosure, the AP 400may be connected with at least one of other electronic devices over awireless communication network through a wireless communication circuit410. The wireless communication circuit 410 may include an antenna, awireless communication chip, or a processor (not shown) that controls anoperation of the wireless communication circuit 410. The operation ofthe wireless communication circuit 410 described below may be controlledby the processor included in the wireless communication circuit 410 ormay be controlled by a processor (not shown) located outside thewireless communication circuit 410 included in the AP 400. The AP 400may perform communication by using various standards such as the IEEE802.11 standards, etc. For example, the AP 400 may perform communicationby using various communication schemes such as WiFi, near-fieldcommunication (NFC), Bluetooth, etc. The wireless communication circuit410 may be configured to support a wireless protocol according tovarious communication schemes.

According to various embodiments of the present disclosure, the wirelesscommunication circuit 410 may encrypt a packet by using variousencryption methods for security of wireless communication, and transmitthe encrypted packet to an external other electronic device. Thewireless communication circuit 410 may perform authentication withrespect to an external another electronic device that attempts anaccess, and perform wireless communication connection with theauthenticated electronic device by using credential information.

According to various embodiments of the present disclosure, the wirelesscommunication circuit 410 may store and manage a list of first channelsat least partially associated with at least one other AP having acoverage overlapping a coverage of the AP 400 among a plurality of APsusing identical credential information at an instant through thewireless communication circuit 410. The wireless communication circuit410 may manage the list of the first channels through another electronicdevice (e.g., a wireless LAN controller (WLC)) that manages an externalserver or a plurality of APs.

According to various embodiments of the present disclosure, the wirelesscommunication circuit 410 may receive information about the firstchannels at least partially associated with the at least one other APfrom the at least one other AP. In another example, the wirelesscommunication circuit 410 may further receive the information about theat least one other AP. The wireless communication circuit 410 mayreceive the information about the first channels and the informationabout the at least one other AP from a server or a WLC that manages theat least one other AP or the plurality of APs including the at least oneother AP.

According to various embodiments of the present disclosure, the wirelesscommunication circuit 410 may generate the list of the first channels byusing the received information about the first channels and store thegenerated list of the first channels in the memory 420.

According to various embodiments of the present disclosure, the wirelesscommunication circuit 410 may generate the list of the first channels byusing the information about the first channels and the information aboutthe at least one other AP. For example, the information about the atleast one other AP may include state information regarding the at leastone other AP, location information regarding the at least one second AP,address information regarding the at least one other AP, or the like.However, this is merely an example for a description, and the presentdisclosure is not limited to the example, such that various informationassociated with the at least one other AP having the coverageoverlapping that of the AP 400 may be used to generate the list of thefirst channels.

According to various embodiments of the present disclosure, the wirelesscommunication circuit 410 may generate the list of the first channelsbefore or after connection with another electronic device. In anotherexample, the wireless communication circuit 410 may generate the list ofthe first channels at the request of the another electronic device. Amethod of generating a channel list will be described later.

According to various embodiments of the present disclosure, the wirelesscommunication circuit 410 may store the list of the second channels atleast partially associated with at least one other AP that does not havea coverage overlapping that of the AP 400 among a plurality of APs inthe memory 420.

According to various embodiments of the present disclosure, the wirelesscommunication circuit 410 may receive information about the secondchannels associated with at least one other AP determined to beconnectable based on a location of the AP 400, even when the at leastone other AP does not have the coverage overlapping that of the AP 400.For example, the wireless communication circuit 410 may receive the listof the second channels at least partially associated with at least oneother AP located within a designated distance from the location of theAP 400, even when the at least one other AP does not have the coverageoverlapping that of the AP 400. In spite of another AP using identicalcredential information, channels at least partially associated with theother AP determined that roaming to the AP is not physically possiblebased on the location of the AP 400 may not be included in the list ofthe second channels.

According to various embodiments of the present disclosure, the wirelesscommunication circuit 410 may generate the list of the second channelsby using the received information about the second channels and storethe generated list of the second channels in the memory 420.

According to various embodiments of the present disclosure, the wirelesscommunication circuit 410 may generate the list of the second channelsby further using the information about the at least one other AP. Forexample, the information about the at least one other AP may includestate information regarding the at least one other AP, locationinformation regarding the at least one second AP, address informationregarding the at least one other AP, or the like. However, this ismerely an example for a description, and the present disclosure is notlimited to the example, such that various information associated withthe at least one other AP that does not have the coverage overlappingthat of the AP 400 may be used to generate the list of the firstchannels and the list of the second channels.

According to various embodiments of the present disclosure, theinformation about the first channels or the information about the secondchannels used to generate the list of the first channels or the list ofthe second channels may be input by a manager managing the plurality ofAPs using the identical credential information.

According to various embodiments of the present disclosure, the list ofthe first channels or the list of the second channels may be generatedas shown in Table 1.

TABLE 1 AP MAC Address 2.4 GHz Channel 5 GHz Channel AA:AA:AA:AA:AA:AA:1 36 BB:BB:BB:BB:BB:BB 6 48 CC:CC:CC:CC:CC:CC 11 149 DD:DD:DD:DD:DD:DD 152 EE:EE:EE:EE:EE:EE 6 36

As shown in Table 1, the list of the first channels may include a mediaaccess control (MAC) address of other APs having a coverage overlappingthat of the AP 400 and information about channels for each bandassociated with the other APs. In another example, the list of the firstchannels may include other information in addition to informationincluded in Table 1. For example, the list of the first channelsincludes CU information about the other APs and information aboutanother AP associated with the other APs. In another example, the listof the second channels may include the MAC address of the other APs thatdo not have a coverage overlapping that of the AP 400 and theinformation about the channels for each band associated with the otherAPs, as shown in Table 1. In another example, the list of the firstchannels may include other information in addition to informationincluded in Table 2. In another example, the list of the second channelsmay include CU information about the other APs. The list of the secondchannels may include information about another AP associated with theother APs.

However, this is merely an example, and the present disclosure is notlimited to the example, and the list of the first channels or the listof the second channels may be generated in various forms includinginformation about channels associated with APs available during scanningfor roaming.

According to various embodiments of the present disclosure, the wirelesscommunication circuit 410 may update a channel list stored in the memory420. For example, the wireless communication circuit 410 may update thelist of the first channels when another AP having a coverage overlappingthat of the AP 400 is added or state information about at least oneother AP having a coverage overlapping that of the AP 400 is changed. Inanother example, the wireless communication circuit 410 may update thelist of the second channels when another AP that does not have acoverage overlapping that of the AP 400 is added or state informationabout at least one other AP that does not have a coverage overlappingthat of the AP 400 is changed.

According to various embodiments of the present disclosure, the wirelesscommunication circuit 410 may provide the list of the first channelsstored in the memory 420 to an external electronic device that iswireless-communication-connected. In another example, the wirelesscommunication circuit 410 may provide the list of the second channelsstored in the memory 420 to an external electronic device that iswireless-communication-connected.

According to various embodiments of the present disclosure, the wirelesscommunication circuit 410 may provide at least one of the list of thefirst channels or the list of the second channels to an externalelectronic device (e.g., the electronic device 101 of FIG. 1, theelectronic device 201 of FIG. 2, or the AP 400 of FIG. 4). In anotherexample, when receiving a request for a channel list from the externalelectronic device, the wireless communication circuit 410 may provide atleast one of the list of the first channels or the list of the secondchannels.

According to various embodiments of the present disclosure, the wirelesscommunication circuit 410 may generate one channel list includinginformation about channels associated with a plurality of APs to whichroaming is possible, without separating the channel list provided toanother electronic device (e.g., the electronic device 101 of FIG. 1)into the list of the first channels or the list of the second channels.The wireless communication circuit 410 may transmit the generatedchannel list to another electronic device.

FIG. 5 is a view for describing roaming of an electronic deviceaccording to a comparison example.

As shown in FIG. 5, when the electronic device 101 (e.g., the electronicdevice 101 of FIG. 1 or the electronic device 201 of FIG. 2) located ina coverage of an AP1 510 (e.g., the AP 400 of FIG. 4) communicates withthe AP1 510 through a wireless communication connection, the electronicdevice 101 may perform roaming when becoming distant from the AP1 510due to movement of the electronic device 101. In another example,although not shown, the electronic device 101 may perform roaming evenwhen a condition of communication with the AP1 510 becomes poor forother reasons.

For example, when the electronic device 101 becomes distant from the AP1 510 due to movement thereof and an RSSI value for the AP 1 510 is lessthan or equal to a designated threshold value, the electronic device 101may determine that roaming is required and perform roaming. In anotherexample, when a CU value for the AP1 510, obtained from the AP1 510, isless than or equal to the designated threshold value, the electronicdevice 101 may determine that roaming is required and perform roaming.In another example, the electronic device 101 may determine from aparameter such as Tx error rate or a signal to noise ratio (SNR) for theAP 1 510 whether roaming is required.

According to an embodiment of the present disclosure, when theelectronic device 101 determines that roaming is required, theelectronic device 101 may perform scanning with respect to at least oneother AP using credential information that is identical to that of theAP1 510. As shown in FIG. 5, when an AP2 520 (e.g., the AP 400 of FIG.4) is found through scanning, the electronic device 101 may reducedisconnection of data communication by performing communicationconnection with the AP2 520.

FIG. 6 is a flowchart illustrating a roaming method of an electronicdevice according to various embodiments of the present disclosure.

In operation 610, the electronic device 101 (e.g., the electronic device101 of FIG. 1 or the electronic device 201 of FIG. 2) may wirelesslyconnect to a first AP (e.g. the AP 400 of FIG. 4) using credentialinformation through a wireless communication circuit of the electronicdevice 101. For example, the electronic device 101 may perform scanningwith respect to at least one connectable AP connectable to perform awireless communication connection. The electronic device 101 may selectthe first AP to be accessed for wireless communication connectionthrough scanning and access the selected first AP by using thecredential information.

In operation 620, the electronic device 101 may receive the list of thefirst channels at least partially associated with the at least onesecond AP (e.g., the AP 400 of FIG. 4) having a coverage overlapping acoverage of the first AP among the plurality of APs using identicalcredential information through the wireless communication circuit. Forexample, the electronic device 101 may send a request for the list ofthe first channels for use in roaming to another device or a server thatmanages the first AP or the plurality of APs. The electronic device 101may receive the list of the first channels from an external electronicdevice or a server that manages the first AP or the plurality of APs, inresponse to the request.

According to various embodiments of the present disclosure, theelectronic device 101 may receive information about the list of thefirst channels from another electronic device or a server that managesthe first AP or the plurality of APs. The electronic device 101 maygenerate and store the list of the first channels based on theinformation about the first channels, when receiving the informationabout the first channels.

In operation 630, the electronic device 101 may perform scanning withrespect to the at least one second AP that uses the credentialinformation by using the received list of the first channels through thewireless communication circuit.

According to various embodiments of the present disclosure, theelectronic device 101 may further receive the list of the secondchannels associated with at least one third AP that does not have acoverage overlapping that of the first AP among the plurality of APs. Inthis case, the electronic device 101 may perform scanning for the atleast one second AP and the at least one third AP that use thecredential information by using the received list of the first channelsand the received list of the second channels.

According to various embodiments of the present disclosure, theelectronic device 101 may perform scanning for channels included in atleast one of the list of the first channels or the list of the secondchannels without needing to perform scanning for available channels. Inthis way, the electronic device 101 may reduce inconvenience caused bydata interruption or power consumption occurring due to scanning throughall available channels.

FIGS. 7A through 7C are views for describing a roaming method of anelectronic device according to various embodiments of the presentdisclosure.

As shown in FIGS. 7A through 7C, a plurality of APs 701, 702, 703, 704,705, and 706 (e.g., the AP 400 of FIG. 4) may have coverages indicatingranges in which wireless communication connection is possible,respectively. Each of the plurality of APs 701, 702, 703, 704, 705, and706 may perform a wireless communication connection with an electronicdevice (e.g., the electronic device 101 of FIG. 1 or the electronicdevice 201 of FIG. 2) located in the coverage.

Referring to FIG. 7A, the electronic device 101 (e.g., the electronicdevice 101 of FIG. 1 or the electronic device 201 of FIG. 2) may performscanning for a wireless communication connection. For example, theelectronic device 101 may perform full scanning that is scanning for allavailable channels. The electronic device 101 may find an AP1 701 (e.g.,the AP 400 of FIG. 4) and an AP2 702 (e.g., the AP 400 of FIG. 4) as aresult of full scanning.

According to an embodiment of the present disclosure, the electronicdevice 101 may perform a wireless communication connection with one ofthe found AP1 701 and AP2 702. For example, for a wireless communicationconnection based on an RSSI value, when an RSSI value of the AP2 702 isgreater than that of the AP1 701, the electronic device 101 may selectthe AP2 702 as an AP that is to be wireless-communication-connected andperform the wireless communication connection with the selected AP2 702.

According to various embodiments of the present disclosure, theelectronic device 101 may perform a connection with the AP2 702 andreceive the list of the first channels associated with the AP1 701, theAP3 703, and the AP4 704 having coverages overlapping the AP2 702 amongthe plurality of APs 701, 702, 703, 704, 705, and 706. The list of thefirst channels may include information about a channel 1, a channel 48,and a channel 11 that are associated with the AP1 701, the AP3 703, andthe AP4 704 having coverages overlapping the AP2 702. In anotherexample, in the list of the first channels, a channel associated withthe AP2 702 may further include information about a channel 36.

According to various embodiments of the present disclosure, theelectronic device 101 may receive information about the first channelsassociated with the AP1 701, the AP3 703, and the AP4 704 havingcoverages overlapping the AP2 702 among the plurality of APs 701, 702,703, 704, 705, and 706, or information about the AP1 701, the AP3 703,and the AP4 704. The electronic device 101 may generate the list of thefirst channels by using the information about the first channelsassociated with the AP1 701, the AP3 703, and the AP4 704, or theinformation about the AP1 701, the AP3 703, and the AP4 704.Hereinbelow, a description will be focused on reception of the list ofthe first channels, but the present disclosure is not limited thereto,such that the electronic device 101 may receive information used togenerate the list of the first channels and generate the list of thefirst channels by using the received information.

According to various embodiments of the present disclosure, theelectronic device 101 may perform a connection with the AP2 702 andreceive the list of the first channels associated with the AP1 701, theAP5 703, and the AP6 704 that do not have the coverages overlapping theAP2 702 among the plurality of APs 701, 702, 705, 706, 705, and 706. Thelist of the second channels may include information about a channel 6and a channel 149 that are associated with the AP5 705 and the AP6 706that do not have coverages overlapping the AP2 702.

According to various embodiments of the present disclosure, theelectronic device 101 may receive the list of the first channels or thelist of the second channels from the AP2 702. In another example, theelectronic device 101 may receive the list of the first channels or thelist of the second channels from another electronic device or a serverthat manages the plurality of APs 701, 702, 703, 704, 705, and 706. Theelectronic device 101 may send a request for the list of the firstchannels or the list of the second channels to another electronic deviceor a server that manages the AP2 702 or the plurality of APs 701, 702,703, 704, 705, and 706. In another example, another electronic device(e.g., the AP 400 or the WLC) or the server that manages the AP2 702 orthe plurality of APs 701, 702, 703, 704, 705, and 706 may transmit thelist of the first channels or the list of the second channels to theelectronic device 101 without receiving a separate request, as detectinga wireless communication connection between the electronic device 101and the AP2 702.

According to various embodiments of the present disclosure, when theelectronic device 101 fails to receive the list of the first channels orthe list of the second channels, the electronic device 101 may performpartial scanning for searching for an AP to which roaming is possiblebased on a result of scanning for the wireless communication connectionwith the AP2 702. For example, partial scanning may indicate scanningfor at least one of available channels rather than scanning for allavailable channels.

For example, as shown in FIG. 7A, the electronic device 101 is locatedin a location where the coverage of the AP1 701 and the coverage of theAP2 702 overlap each other, such that the electronic device 101 maysearch for the AP1 701 and the AP2 702 through scanning and may includeinformation about the channel 1 and the channel 36 associated with thefound AP1 701 and AP2 702. When a condition of communication with theAP2 702 that is wireless-communication-connected with the electronicdevice 101 becomes poor due to movement of the electronic device 101 orother reasons, the electronic device 101 may perform partial scanningthrough the channel 1 and the channel 36.

According to various embodiments of the present disclosure, when theelectronic device 101 includes information about channels associatedwith APs found based on a result of scanning, the electronic device 101may not include information about all channels associated with APs towhich roaming is possible. The electronic device 101 may not find an APto which roaming is possible, through partial scanning. The electronicdevice 101 may have to perform full scanning that is scanning for allavailable channels, when an AP to which roaming is possible is not foundthrough partial scanning. Full scanning is scanning for all availablechannels, such that much time is required for partial scanning, and auser may experience data interruption due to an increase in the requiredtime and a loss may occur in use of a channel. The electronic device 101may consume as much current as the increase in the required time.

According to various embodiments of the present disclosure, theelectronic device 101 may receive the list of the first channels or thelist of the second channels, thus obtaining information about channelsassociated with APs to which roaming is possible. When a condition ofcommunication with the AP2 702 wireless-communication-connected with theelectronic device 101 becomes poor due to movement of the electronicdevice 101 or other reasons, the electronic device 101 may find an AP towhich roaming is possible through partial scanning by using the receivedlist of the first channels or the received list of the second channels.

As shown in FIG. 7B, the electronic device 101 may move from a locationwhere the coverage of the AP1 701 and the coverage of the AP2 702overlap each other to a location where the coverage of the AP3 703 andthe coverage of the AP4 704 overlap each other. As a condition ofcommunication with the wirelessly connected AP2 702 becomes poor due tomovement of the electronic device 101, the electronic device 101 mayperform partial scanning by using the list of the first channels or thelist of the second channels in a point 711.

According to an embodiment of the present disclosure, the electronicdevice 101 may identify information about the channel 1, the channel 48,and the channel 11 that are associated with the AP1 701, the AP3 703,and the AP4 704 from the list of the first channels. Based on theidentified information about the channel 1, the channel 48, and thechannel 11, the electronic device 101 may perform partial scanning withrespect to APs to which roaming is possible through the channel 1, thechannel 48, and the channel 11, when the electronic device 101 islocated in the point 711. The electronic device 101 may find the AP3 703and the AP4 704 as a result of partial scanning and perform roamingthrough a wireless communication connection with one of the found AP3703 and AP4 704. For example, for a wireless communication connectionbased on an RSSI value, when an RSSI value of the AP4 704 is greaterthan that of the AP3 703, the electronic device 101 may select the AP4704 as an AP that is to be wireless-communication-connected. Theelectronic device 101 may perform roaming through a wirelesscommunication connection with the AP4 704.

As shown in FIG. 7C, for example, based on the identified informationabout the channel 1, the channel 48, and the channel 11, the electronicdevice 101 may perform partial scanning with respect to APs to whichroaming is possible through the channel 1, the channel 48, and thechannel 11, when the electronic device 101 is located in the point 721.The electronic device 101 may find the AP3 703 and the AP4 704 as aresult of partial scanning and perform roaming through a wirelesscommunication connection with one of the found AP3 703 and AP4 704. Forexample, for a wireless communication connection based on an RSSI value,when an RSSI value of the AP3 703 is greater than that of the AP3 703,the electronic device 101 may select the AP3 703 as an AP that is to bewireless-communication-connected. The electronic device 101 may performroaming through a wireless communication connection with the AP3 704.

According to various embodiments of the present disclosure, whenperforming partial scanning with respect to APs to which roaming ispossible by using the list of the first channels or the list of thesecond channels, the electronic device 101 may obtain a CU valueassociated with the APs from the APs to which roaming is possible. Theelectronic device 101 may compare the CU value associated with each ofthe APs with a designated threshold value. The electronic device 101 maydetermine at least one AP with respect to which partial scanning is tobe performed from among the APs based on a result of comparison, andperform partial scanning with respect to the determined at least one AP.

Referring to FIG. 7B, the electronic device 101 may obtain CU valuesassociated with the AP1 701, the AP3 703, and the AP4 704 whenperforming partial scanning by using the list of the first channels orthe list of the second channels in the point 711. When the electronicdevice 101 determines that a CU for the channel 48 associated with theAP3 703 is high, as a result of comparing the CU values associated withthe AP1 701, the AP3 703, and the AP4 704 with the designated thresholdvalue, the electronic device 101 may not perform scanning with respectto the AP3 703 through the channel 48.

Referring to FIG. 7B, when the electronic device 101 determines that theCU value for the channel 48 associated with the AP3 703 is high, andthus performs scanning with respect to the AP3 703 through the channel48, the electronic device 101 may perform a wireless communicationconnection with the AP4 704 found through partial scanning except forthe AP3 703.

According to various embodiments of the present disclosure, when theelectronic device 101 does not receive the list of the first channels orthe list of the second channels, the electronic device 101 may performpartial scanning with respect to APs to which roaming is possiblethrough the channels 1 and 36 that are associated with the AP1 701 andthe AP2 702 found through scanning in the wireless communicationconnection with the AP2 702 in the point 711. In this case, theelectronic device 101 may not find the AP3 703 and the AP4 704 usingpartial scanning through the channels 1 and 36, and thus the electronicdevice 101 may need to perform full scanning with respect to allavailable channels in a point 712 to search for an AP to which roamingis possible. The electronic device 101 may find the AP3 703 and the AP4704 through full scanning and perform roaming through a wirelesscommunication connection with one of the found AP3 703 and AP4 704. Assuch, when the electronic device 101 does not receive the list of thefirst channels or the list of the second channels, the electronic device101 may need to perform full scanning, and thus a time required forroaming may increase.

As shown in FIG. 7C, the electronic device 101 according to anembodiment of the present disclosure may perform partial scanning withrespect to APs to which roaming is possible through the channels 1 and36 in a point 721. In this case, the electronic device 101 may not findthe AP3 703 and the AP4 704 using partial scanning, and thus theelectronic device 101 may need to perform full scanning with respect toall available channels in a point 722 to search for an AP to whichroaming is possible. The electronic device 101 may find the AP3 703 andthe AP4 704 through full scanning and perform roaming through a wirelesscommunication connection with one of the found AP3 703 and AP4 704. Whenthe electronic device 101 does not receive the list of the firstchannels or the list of the second channels, the electronic device 101may need to perform full scanning, and thus a time required for roamingmay increase.

FIG. 8 is a flowchart illustrating a method of updating a list ofchannels by an electronic device, according to various embodiments ofthe present disclosure.

In operation 810, after the electronic device 101 (e.g., the electronicdevice 101 of FIG. 1 or the electronic device 201 of FIG. 2) performsscanning with respect to at least one second AP (e.g., the AP1 701, theAP3 703, and the AP4 704 of FIG. 7B) having a coverage overlapping thatof a first AP (e.g., the AP2 702 of FIG. 7B)wireless-communication-connected with the electronic device 101, theelectronic device 101 may perform the wireless communication connectionwith one (e.g., the AP4 704 of FIG. 7B) of the at least one second AP byusing credential information. For example, the electronic device 101 mayobtain at least one of an RSSI value or a CU value for each of the atleast one second AP. The electronic device 101 may select an AP that isto wireless-communication-connected from among the at least one secondAP, by using at least one of the obtained RSSI value or CU value foreach of the at least one second AP. The electronic device 101 mayperform the wireless communication connection with the AP selected fromamong the at least one second AP.

Referring to FIG. 7B, the electronic device 101 may perform a wirelesscommunication connection with the AP4 704 based on the RSSI value, whenthe electronic device 101 is located in a location where the coverage ofthe AP3 703 and the coverage of the AP4 704 overlap each other. Inanother example, even for the RSSI value of the AP4 704 that is greaterthan the RSSI value of the AP3 703, when the electronic device 101determines that utilization of the channel 11 associated with the AP4704 is higher based on the CU value for the AP4 704, the electronicdevice 101 may perform a wireless communication connection with the AP3703 having the smaller RSSI value. In another example, the electronicdevice 101 may select an AP that is to wireless-communication-connected,based on the RSSI values and the CU values of the AP3 703 and the AP4704.

In operation 820, the electronic device 101 may receive the list of thethird channels associated with the at least one fourth AP (e.g., the AP2702, the AP3 703, the AP5 705, and the AP6 706 of FIG. 7B) havingcoverages overlapping a wireless-communication-connected AP (e.g., theAP4 704 of FIG. 7B) in operation 810 among the plurality of APs usingthe identical credential information. Referring to FIG. 7B, theelectronic device 101 may receive the list of the third channelsassociated with the AP2 702, the AP3 703, the AP5 705, and the AP6 706having the coverages overlapping the wireless-communication-connectedAP4 704. The list of the third channels may include information aboutthe channel 36, the channel 48, the channel 6, and the channel 149 thatare associated with the AP2 702, the AP3 703, the AP5 705, and the AP6706. In another example, the list of the third channels may furtherinclude information about the channel 11 associated with the AP4 704.

In operation 830, the electronic device 101 may update the list of thefirst channels by using the received list of the third channels. As theelectronic device 101 performs a wireless communication connection withone (e.g., the AP4 704 of FIG. 7B) of the at least one second AP inoperation 810 and a wireless communication connection with the first AP(e.g., the AP1 701 of FIG. 7B) is released, the electronic device 101may update the list of the first channels, which is a list of channelsused for existing roaming based on the currently connected AP (e.g., theAP4 704 of FIG. 7B), by using the list of the third channels.

According to various embodiments of the present disclosure, theelectronic device 101 may compare the list of the first channels withthe list of the third channels, identify channels that are not includedin the list of the first channels from among the third channels includedin the list of the third channels, and add the identified channels tothe list of the first channels, thereby updating the list of the firstchannels. In another example, the electronic device 101 may update thelist of the third channels by using the list of the first channels inthe same manner.

Referring to FIG. 7B, the list of the first channels may includeinformation about the channel 1, the channel 36, the channel 48, and thechannel 11, and the list of the third channels may include informationabout the channel 36, the channel 48, the channel 6, and the channel149. The electronic device 101 may determine that the channels 6 and 149included in the list of the third channels are not included in the listof the first channels, and add the information about the channels 6 and149 to the list of the first channels. Thus, the list of the firstchannels may be updated to include information about the channel 1, thechannel 36, the channel 48, the channel 11, the channel 6, and thechannel 149. The updated list of the first channels may be used when theelectronic device 101 performs roaming later.

According to various embodiments of the present disclosure, theelectronic device 101 may further receive the list of the secondchannels associated with the at least one third AP (e.g., the AP5 705and the AP6 706 of FIG. 7B) that does not have coverages overlappingthat of the first AP (e.g., the AP2 702 of FIG. 7B). When informationincluded in the list of the first channels and the list of the secondchannels is identical to information about channels included in the listof the third channels, the electronic device 101 may not update thechannel list.

FIG. 9 is a flowchart illustrating a method of determining whether toperform scanning for roaming by an electronic device, according tovarious embodiments of the present disclosure.

In operation 910, the processor (e.g., the processor 120) of theelectronic device 101 (e.g., the electronic device 101 of FIG. 1 and theelectronic device 201 of FIG. 2) may monitor at least one of the RSSIvalue or the CU value for the first AP after performing the wirelesscommunication connection with the first AP (e.g., the AP 400 of FIG. 4).For example, the electronic device 101 may monitor at least one of theRSSI value or the CU value for the first AP by obtaining at least one ofthe RSSI value or the CU value for the first AP according to adesignated period.

In another example, the processor may continuously monitor the CU valuefor the first AP after performing the wireless communication connectionwith the first AP, or monitor the CU value for the first AP when theRSSI for the first AP satisfies a designated condition.

For example, the processor may continuously monitor the CU value for thefirst AP after performing a wireless communication connection with thefirst AP regardless of the RSSI value for the first AP.

In another example, in operation 920, the processor may identify the CUvalue for the first AP by performing monitoring with respect to the CUvalue for the first AP, when the RSSI for the first AP exceeds adesignated first threshold value.

In another example, in operation 930, the processor may identify the CUvalue for the first AP by performing monitoring with respect to the CUvalue for the first AP, when the RSSI for the first AP exceeds thedesignated first threshold value and is less than or equal to adesignated second threshold value.

In operation 920, the processor may determine whether the RSSI value forthe first AP is less than or equal to the designated first thresholdvalue (e.g., −75 dBm). For example, the electronic device 101 maydetermine whether the electronic device 101 is out of the coverage ofthe first AP, by determining whether the RSSI value for the first AP isless than or equal to the first threshold value.

In operation 950, the processor may perform scanning with respect to anAP to which roaming is possible, to perform roaming, when the RSSI valuefor the first AP is less than or equal to the first threshold value.When the RSSI value for the first AP is less than or equal to the firstthreshold value, the electronic device 101 may determine that theelectronic device 101 is out of the coverage of the first AP and performscanning with respect to an AP to which roaming is possible, by using achannel list.

In operation 930, the processor may determine whether the RSSI value forthe first AP is less than or equal to the designated second thresholdvalue (e.g., −65 dBm). For example, when the RSSI value for the first APexceeds the first threshold value and thus the electronic device 101determines that the electronic device 101 is not out of the coverage ofthe first AP, the processor may perform scanning with respect to an APto which roaming is possible, based on the RSSI value for the first AP.Even when the electronic device 101 is not out of the coverage of thefirst AP, the electronic device 101 may compare the RSSI value for thefirst AP with the first threshold value and the second threshold valueto determine whether to perform scanning with respect to an AP to whichroaming is possible.

In operation 940, the processor may determine whether the CU value forthe first AP is greater than or equal to the designated third thresholdvalue (e.g., about 70%) when the RSSI value for the first AP exceeds thefirst threshold value and is less than or equal to the second thresholdvalue. For example, when the RSSI value for the first AP is less than orequal to the second threshold value, the processor may determine whetherto perform scanning with respect to an AP to which roaming is possible,based on a complexity of a channel associated with the first AP, evenwhen the electronic device 101 is not out of the coverage of the firstAP. For example, the processor may determine the complexity of thechannel associated with the first AP by determining whether the CU valuefor the first AP is greater than the third threshold value. For example,when the RSSI value for the first AP exceeds the first threshold valueand is less than or equal to the second threshold value, the electronicdevice 101 may perform scanning with respect to an AP to which roamingis possible, by determining the complexity of the channel associatedwith the first AP, even when the electronic device 101 is not out of thecoverage of the first AP. For example, the electronic device 101 maydetermine the complexity of the channel, the usability of the channel,etc., by further using a bandwidth, an MCS index, and/or an RSSI value.

In operation 950, the processor may perform scanning with respect to anAP to which roaming is possible, to perform roaming, by using thechannel list, when the CU value for the first AP is greater than orequal to the third threshold value. When the CU value for the first APis greater than the third threshold value, the electronic device 101 maydetermine that the complexity of the channel associated with the firstAP increases, and perform scanning with respect to an AP to whichroaming is possible, by using the channel list even when the electronicdevice 101 is not out of the coverage of the first AP.

FIGS. 10A and 10B are views for describing a method of determiningwhether to perform scanning for roaming by an electronic device,according to various embodiments of the present disclosure.

As shown in FIG. 10A, when a first AP 1010 (e.g., the AP 400 of FIG. 4)and a second AP 1020 (e.g., the AP 400 of FIG. 4) using identicalcredential information are installed in a cafe, the electronic device101 may perform full scanning through all available channels through awireless communication connection when the electronic device 101 (e.g.,the electronic device 101 of FIG. 1 or the electronic device 201 of FIG.2) enters the cafe. The electronic device 101 may perform the wirelesscommunication connection with one of the AP1 1010 and the AP2 1020 foundas a result of the full scanning. When another electronic device doesnot exist in a cafe as shown in FIG. 10A, the electronic device 101 mayselect an AP that is to be wireless-communication-connected based on theRSSI values of the AP1 1010 and the AP2 1020. For example, based on theRSSI values of the AP1 1010 and the AP2 1020, the electronic device 101may perform the wireless communication connection with the AP1 1010having the greater RSSI value between the AP1 1010 and the AP2 1020.

As shown in FIG. 10B, after the electronic device 101 performs thewireless communication connection with the AP1 1010, other electronicdevices 1001, 1002, 1003, 1004, 1005, and 1006 may enter the coverage ofthe AP1 1010 and may perform the wireless communication connection withthe AP1 1010. As the other electronic devices 1001 perform the wirelesscommunication connection with the AP1 1010, data transmitted andreceived through a channel associated with the AP1 1010 increases andthus a CU value for the AP1 1010 may increase. When the electronicdevice 101 considers an RSSI value without considering a CU value todetermine whether to perform scanning for roaming, the electronic device101 continuously maintains the wireless communication connection withthe AP1 1010, reducing the speed of data transmission and receptionthrough the channel associated with the AP1 1010.

According to various embodiments of the present disclosure, theelectronic device 101 may determine whether to perform scanning forroaming through the CU value for the AP1 1010 even when the RSSI valuefor the AP1 1010 does not satisfy a condition for performing scanningfor roaming. For example, as shown in FIG. 10B, when the RSSI value forthe AP1 1010 exceeds the designated first threshold value and is lessthan or equal to the designated second threshold value, and the CU valuefor the AP1 1010 is greater than or equal to the designated thresholdvalue, the electronic device 101 may perform scanning with respect toAPs to which roaming is possible, by using a channel list for roaming.The electronic device 101 may find the AP2 1020 as a result of scanningand perform a wireless communication connection with the AP2 1020, thusperforming roaming. As shown in FIG. 10B, the AP2 1020 has performed thewireless communication connection only with another electronic device1007, and thus a CU value for the AP2 1020 may be less than the CU valuefor the AP1 1010. In this way, the electronic device 101 performsroaming from the AP1 1010 to the AP2 1020, such that the speed of datatransmission and reception may not be reduced.

FIGS. 11A and 11B are flowcharts illustrating a method of adjusting adwell time by an electronic device, according to various embodiments ofthe present disclosure.

FIG. 11A is a flowchart of a method of adjusting a dwell time for atleast one channel among channels associated with at least one AP forwhich scanning is to be performed, according to various embodiments ofthe present disclosure.

In operation 1110, the processor (e.g., the processor 120) of theelectronic device 101 (e.g., the electronic device 101 of FIG. 1 and theelectronic device 201 of FIG. 2) may determine complexities of channelsassociated with at least one AP (e.g., the AP 400 of FIG. 4) to whichroaming is possible, by using a received channel list. For example, theelectronic device 101 may determine the complexities of the channelsassociated with the at least one AP by identifying the degree of use ofthe channels or a time during which the channels are occupied.

In operation 1120, the processor may determine whether the determinedcomplexities of the channels associated with the at least one AP aregreater than a designated threshold value. For example, the processormay determine that at least one channel having a complexity greater thanor equal to the threshold value among the channels associated with theat least one AP is a complex channel that is used by a large amount oroccupied for a long time.

In operation 1130, the processor may adjust a dwell time for at leastone of the channels associated with the at least one channel having thecomplexity greater than or equal to the threshold value among thechannels associated with the at least one AP. For example, theelectronic device 101 may increase the dwell time for the at least onechannel determined to be complex.

FIG. 11B is a flowchart of a method of adjusting a dwell time for allchannels associated with at least one AP to which roaming is possible,according to various embodiments of the present disclosure.

In operation 1140, the processor (e.g., the processor 120) of theelectronic device 101 (e.g., the electronic device 101 of FIG. 1 and theelectronic device 201 of FIG. 2) may determine whether the number ofchannels associated with the at least one AP to which roaming ispossible is less than or equal to a designated value, by using areceived channel list.

In operation 1150, the processor may adjust the dwell time for thechannels associated with the at least one AP, when the number ofchannels associated with the at least one AP to which roaming ispossible is less than or equal to the designated value. For example, theelectronic device 101 may increase the dwell time for the channelsassociated with the at least one AP.

FIGS. 12A through 12C are views for describing adjustment of a dwelltime by an electronic device, according to various embodiments of thepresent disclosure.

For convenience of a description, it is assumed in FIGS. 12A through 12Cthat an AP1 is associated with a channel 6, an AP2 is associated with achannel 11, an AP3 is associated with a channel 36, and an AP4 isassociated with a channel 100.

As shown in FIG. 12A, the electronic device (e.g., the electronic device101 of FIG. 1 or the electronic device 201 of FIG. 2) according to anembodiment of the present disclosure may apply a fixed dwell time tochannels associated with APs (e.g., the AP 400 of FIG. 4) to whichroaming is possible. For example, the electronic device may send a proberequest through the channel 6 at a time point 1201 and wait for a fixeddwell time d₁ (e.g., 40 ms) to receive a probe response from the AP1associated with the channel 6. The electronic device may find the AP1when receiving the probe response from the AP1 through the channel 6within the fixed dwell time d₁. For example, the dwell time may be fixedto a value determined according to which roaming is performed, or may befixed to a value differing according to passive scanning or activescanning.

The electronic device may send a probe request through the channel 11 ata time point 1203, and find the AP2 upon receiving a probe response fromthe AP2 associated with the channel 11 at a time point 1204 within thefixed dwell time d₁.

The electronic device may send a probe request through the channel 36 ata time point 1205 and wait for the fixed dwell time d₁ to receive aprobe response from the AP3 associated with the channel 36. However,when the AP3 fails to obtain a channel for sending a probe response dueto a high complexity of the channel 36 or a load of the AP3 occurs, theprobe response sent by the AP3 may not be received in the electronicdevice within the fixed dwell time. When the electronic device fails toreceive the probe response from the AP3 through the channel 36 withinthe fixed dwell time d₁, the electronic device may not find the AP3.

Thereafter, the electronic device may switch from the channel 36 to thechannel 100 associated with the AP4 at a time point 1206, and send aprobe request through the channel 100. Thus, even when the AP3 sends aprobe response through the channel 36 at a time point 1207, theelectronic device may not receive the probe response sent by the AP3through the channel 36 because the electronic device has alreadyswitched to the channel 100.

When the fixed dwell time is applied regardless of complexities ofchannels, at least one of APs to which roaming is possible may not befound. When the unfound AP3 is a sole AP to which roaming of theelectronic device is possible, the electronic device needs to performadditional scanning, increasing a time required for scanning. When theunfound AP3 is an AP having the best condition of a wirelesscommunication connection with the electronic device among APs to whichroaming is possible, the electronic device may perform the wirelesscommunication connection with another AP having a poorer condition ofthe wireless communication connection than that of the AP3, increasing apossibility of additional roaming. As a result, the aforementioned datainterruption or electric current consumption may occur.

Referring to FIG. 12B, the electronic device 101 according to variousembodiments of the present disclosure may adjust a dwell time for atleast one of channels associated with the APs to which roaming ispossible.

The electronic device 101 may send a probe request through the channels6 and 11 at time points 1211 and 1213. The electronic device 101 mayreceive a probe response from the AP1 associated with the channel 6 andthe AP2 associated with the channel 11 through the channel 6 and thechannel 11 and find the AP1 and the AP2 upon receiving the proberesponse.

The electronic device 101 may send a probe request through the channel36 at a time point 1215. The electronic device 101 may determine acomplexity of the channel 36. The processor 101 may determine thecomplexity of the channel 36 by identifying the amount of use of thechannel 36, a time for which the channel 36 is occupied, etc.

The electronic device 101 may determine whether the complexity of thechannel 36 is greater than or equal to a designated fourth thresholdvalue. When the complexity of the channel 36 is greater than or equal tothe designated fourth threshold value, the electronic device 101 maydetermine that the channel 36 is a complex channel that is used by alarge amount or occupied for a long time. Thus, the electronic device101 may adjust the dwell time for the channel 36 from d₁ (e.g., 40 ms)to d₂ (e.g., 80 ms). However, this is merely an example for adescription, and the electronic device 101 may determine the degree ofadjustment for the dwell time depending on the complexity of the channel36.

By adjusting the dwell time for the channel 36, the electronic device101 may wait for the adjusted dwell time d₂ to receive the proberesponse from the AP3 without switching from the channel 36 to thechannel 100 at a time point 1216.

As shown in FIG. 12B, the electronic device 101 may find the AP3 uponreceiving the probe response from the channel 36 from the AP3 at a timepoint 1217. Thereafter, the electronic device 101 may switch from thechannel 36 to the channel 100 at a time point 1218 after an elapse ofthe adjusted dwell time, and send a probe request through the channel100.

As the electronic device 101 adjusts a dwell time for a channel based ona complexity of the channel in this way, it is possible to prevent adelay in reception of a probe response, caused by a complex state of thechannel or occurrence of a load in an AP, and thus a failure in findingthe AP from occurring.

Referring to FIG. 12C, the electronic device 101 according to variousembodiments of the present disclosure may adjust a dwell time for allchannels associated with the APs to which roaming is possible.

According to an embodiment of the present disclosure, the electronicdevice 101 may identify the number of channels associated with at leastone AP to which roaming is possible, through a list of channels used forroaming. The electronic device 101 may determine whether the identifiednumber of channels associated with the at least one AP is less than orequal to a designated value. The electronic device 101 may adjust thedwell time d₁ for all of the channels associated with the at least oneAP to d₂, when the identified number of channels associated with the atleast one AP is less than or equal to the designated value. For example,when the number of channels associated with the at least one AP isidentified as 3 and the designated value is 4, the electronic device 101may adjust the dwell time for all of the channels associated with the atleast one AP. The electronic device may, for example, increase the dwelltime.

The electronic device 101 may send the probe request through the channel6 at a time point 1221, may not send the probe request through thechannel 11 at a time point 1223 based on an existing dwell time, andsend the probe request through the channel 11 at a time point 1224 basedon an adjusted dwell time. The electronic device 101 may not send theprobe request through the channel 36 at a time point 1225 based on theexisting dwell time and may send the probe request through the channel36 at a time point 1227.

The electronic device 101 may find the first AP upon receiving the proberesponse from the AP1 through the channel 6 at a time point 1222. Thetime point 1222 at which the probe response is received from the AP1falls within the existing dwell time, such that the AP1 may be foundwithout adjustment of the dwell time.

The electronic device 101 may receive the probe response from the AP2through the channel 11 at a time point 1226 and thus find the AP2. Thetime point 1226 at which the probe response is received from the AP2follows the elapse of the existing dwell time, but falls within theadjusted dwell time, such that the AP2 may also be found.

As the electronic device 101 adjusts a dwell time for channels based onthe number of channels associated with at least one AP to which roamingis possible, it is possible to prevent a delay in reception of a proberesponse, caused by a complex state of the channel or occurrence of aload in an AP, and thus a failure in finding the AP from occurring.

FIG. 13 is a flowchart illustrating a method of performing additionalscanning by an electronic device, according to various embodiments ofthe present disclosure.

In operation 1310, the processor (e.g., the processor 120) of theelectronic device 101 (e.g., the electronic device 101 of FIG. 1 and theelectronic device 201 of FIG. 2) may identify complexities of channelsassociated with the at least one AP to which roaming is possible, byusing a received channel list. For example, the processor may determinethe complexities of the channels associated with the at least one AP byidentifying the degree of use of the channels or a time during which thechannels are occupied.

In operation 1320, the processor may determine whether the determinedcomplexities of the channels associated with the at least one AP aregreater than a designated threshold value. For example, the processormay determine that at least one channel having a complexity greater thanor equal to a designated threshold value among the channels associatedwith the at least one AP (e.g., the AP 400 of FIG. 4) is a complexchannel that is used by a large amount or occupied for a long time.

In operation 1330, the processor may perform additional scanning withrespect to the at least one channel having the complexity greater thanor equal to the designated threshold value among the channels associatedwith the at least one AP.

FIG. 14 is a view for describing a method of performing additionalscanning by an electronic device, according to various embodiments ofthe present disclosure.

Referring to FIG. 14, the electronic device (e.g., the electronic device101 of FIG. 1 or the electronic device 201 of FIG. 2) according tovarious embodiments of the present disclosure may perform additionalscanning with respect to at least one of the channels associated withAPs (e.g., the AP 400 of FIG. 4) to which roaming is possible. Forconvenience of a description, it is assumed in FIG. 14 that the AP1 isassociated with the channel 6, the AP2 is associated with the channel11, and the AP3 is associated with the channel 36.

The electronic device 101 may send a probe request through the channel 6at a time point 1401. The electronic device 101 may determine acomplexity of the channel 6. The processor 101 may determine thecomplexity of the channel 6 by identifying the amount of use of thechannel 6, a time for which the channel 6 is occupied, etc.

The electronic device 101 may determine whether the complexity of thechannel 6 is greater than or equal to a designated threshold value. Whenthe complexity of the channel 6 is greater than or equal to thedesignated threshold value, the electronic device 101 may determine thatthe channel 6 is a complex channel. When the electronic device 101 failsto receive the probe response from the AP 1 associated with the channel6 within the dwell time for the channel 6, the electronic device 101 maydetermine to perform additional scanning with respect to the channel 6.

Referring to FIG. 14, the electronic device 101 may find the AP1 byreceiving the probe response from the AP1 associated with the channel 6at a time point 1402 within the dwell time for the channel 6. In thiscase, the electronic device 101 may not perform additional scanning withrespect to the channel 6 even when determining the channel 6 to be acomplex channel.

The electronic device 101 may switch from the channel 6 to the channel11 at a time point 1403 and send a probe request through the channel 11.The electronic device 101 may determine a complexity of the channel 11.The electronic device 101 may determine whether the complexity of thechannel 11 is greater than or equal to the designated threshold value.When the electronic device 101 fails to receive the probe response fromthe AP2 associated with the channel 11 within the dwell time for thechannel 11, the electronic device 101 may determine to performadditional scanning with respect to the channel 11.

Referring to FIG. 14, the electronic device 101 may switch from thechannel 11 to the channel 36 at a time point 1404 after the elapse ofthe dwell time of the channel 11, and send a probe request through thechannel 36. Thus, even when the AP2 sends a probe response through thechannel 11 at a time point 1405, the electronic device 101 may notreceive the probe response sent by the AP2 through the channel 11because the electronic device 101 has already switched to the channel36. The electronic device 101 may then determine to perform additionalscanning with respect to the channel 11. The electronic device 101 mayreceive a probe response from the AP3 associated with the channel 36through the channel 36 at a time point 1406 within the dwell time of thechannel 36 and thus find the AP3.

The electronic device 101 may re-send the probe request through thechannel 11 at a time point 1407 following completion of scanning throughchannels included in a received channel list.

As shown in FIG. 14, the electronic device 101 may receive a proberesponse from the AP2 through the channel 11 at a time point 1408 withinthe dwell time of the channel 11 in response to the probe request sentthrough the channel 11 at the time point 1407, and thus find the AP2.

As the electronic device 101 performs additional scanning with respectto a channel based on a complexity of the channel in this way, it ispossible to prevent a delay in reception of a probe response, caused bya complex state of the channel or occurrence of a load in an AP, andthus a failure in finding the AP from occurring.

FIG. 15 is a flowchart illustrating a method of providing a list ofchannels by an AP, according to various embodiments of the presentdisclosure.

In operation 1510, a wireless communication circuit (e.g., the wirelesscommunication circuit 410) of an AP (e.g., the AP 400 of FIG. 4) maygenerate and store a list of first channels at least partiallyassociated with at least one first AP (e.g., the AP 400 of FIG. 4)having a coverage overlapping that of the AP 400 among a plurality ofAPs (e.g., the AP 400 of FIG. 4) using identical credential informationat a time point. The wireless communication circuit may receiveinformation about the first channels at least partially associated withthe at least one first AP from the at least one first AP. In anotherexample, the wireless communication circuit may receive informationabout the first channels from another electronic device (e.g., a WLC) ora server that manages the plurality of APs.

According to various embodiments of the present disclosure, the wirelesscommunication circuit may generate the list of the first channels byusing the received information about the first channels and store thegenerated list of the first channels.

According to various embodiments of the present disclosure, the wirelesscommunication circuit may generate and store the list of the secondchannels at least partially associated with at least one second AP(e.g., the AP 400 of FIG. 4) that does not have a coverage overlappingthat of the AP 400 among the plurality of APs. The wirelesscommunication circuit may receive information about the second channelsat least partially associated with at least one second AP located withina designated distance from the location of the AP 400, even when the atleast one second AP does not have the coverage overlapping that of theAP 400. The wireless communication circuit may generate the list of thesecond channels by using the received information about the secondchannels and store the generated list of the second channels.

In operation 1520, the wireless communication circuit may perform awireless communication connection with an electronic device (e.g., theelectronic device 101 of FIG. 1 or the electronic device 201 of FIG. 2)located in the coverage of the AP 400.

In operation 1530, the wireless communication circuit may provide thestored list of the first channels or the stored list of the secondchannels to the wireless-communication-connected electronic device 101.For example, the wireless communication circuit may provide the list ofthe first channels or the list of the second channels to the electronicdevice 101 at the request of the electronic device 101. In anotherexample, the wireless communication circuit may provide the list of thefirst channels or the list of the second channels to the electronicdevice 101 without a separate request, as a wireless communicationconnection with the electronic device 101 is performed.

FIGS. 16A through 16D are flowcharts illustrating a method of providinga list of channels between an AP and an electronic device, according tovarious embodiments of the present disclosure.

Referring to FIG. 16A, in operation 1610, an AP1 1610 (e.g., the AP 400of FIG. 4) may transmit channel information associated with the AP1 1601to an AP2 1602 (e.g., the AP 400 of FIG. 4). The AP1 1601 may furthertransmit information about the AP1 1601. The AP1 1601 and the AP2 1602may use identical credential information.

In operation 1611, the AP2 1602 may generate a list of channelsassociated with the AP1 1601 and the AP2 1602, based on at least one ofthe channel information associated with the AP1 1601 or the informationabout the AP1 1601, which is received from the AP1 1601.

In operation 1612, the AP2 1602 may transmit the generated list of thechannels associated with the AP1 1601 and the AP2 1602 to the AP1 1601.The AP1 1601 may store the received list of the channels associated withthe AP1 1601 and the AP2 1602 received from the AP2 1602.

In operations 1613 and 1614, the electronic device 101 (e.g., theelectronic device 101 of FIG. 1 or the electronic device 201 of FIG. 2)may perform scanning with respect to at least one connectable AP toperform a wireless communication connection.

In operation 1615, the electronic device 101 may perform the wirelesscommunication connection with one of the AP 11601 and the AP2 1602 foundas a result of the scanning.

In operation 1616, the electronic device 101 may send a request for alist of channels used to perform roaming to thewireless-communication-connected AP1 1601.

In operation 1617, the AP1 1601 may send the stored list of the channelsassociated with the AP1 1601 and the AP2 1602 to the electronic device101, in response to the request sent from the electronic device 101.

In operation 1618, the electronic device 101 may store the list of thechannels associated with the AP1 1601 and the AP2 1602 received from theAP1 1601. When generating the list of the channels in operations 1613and 1614, the electronic device 101 may update the generated list of thechannels by using the received list of the channels associated with theAP1 1610 and the AP2 1602.

Referring to FIG. 16B, in operation 1621, the AP1 1601 may transmitchannel information associated with the AP1 1601 to the AP2 1602. TheAP1 1601 may further transmit information about the AP1 1601 to the AP21602.

In operation 1622, the AP2 1602 may generate a list of channelsassociated with the AP1 1601 and the AP2 1602, based on at least one ofthe channel information associated with the AP 11601 or the informationabout the AP 11601, which is received from the AP1 1601.

In operations 1623 and 1624, the electronic device 101 may performscanning with respect to at least one connectable AP to perform awireless communication connection.

In operation 1625, the electronic device 101 may perform the wirelesscommunication connection with one of the AP 11601 and the AP2 1602 foundas a result of the scanning.

In operation 1626, the electronic device 101 may send a request for alist of channels used to perform roaming to thewireless-communication-connected AP1 1601.

In operation 1627, the AP1 1601 may send a request for the list of thechannels to the AP2 1602 because the AP1 1601 does not store the list ofthe channels.

In operation 1628, the AP2 1602 may send the generated list of thechannels associated with the AP1 1601 and the AP2 1602 to the AP1 1601,in response to the request sent from the AP1 1601.

In operation 1629, the AP1 1601 may send the list of the channelsassociated with the AP1 1601 and the AP2 1602 received from the AP2 1602to the electronic device 101.

In operation 1630, the electronic device 101 may store the list of thechannels associated with the AP1 1601 and the AP2 1602 received from theAP1 1601.

Referring to FIGS. 16A and 16B, when the AP1 1601wireless-communication-connected with the electronic device 101 does notself-generate a channel list, the AP1 1601 may receive the channel listfrom the AP2 1602 that is another AP, and may transmit the receivedchannel list to the electronic device 101.

Referring to FIG. 16C, in operation 1631, the AP 11601 may send a signalfor identifying an AP located at a close distance. For example, thesignal may include at least one of information about a channelassociated with the AP1 1601 or information about the AP1 1601.

In operation 1632, the AP2 1602 may send a signal for identifying an APlocated at a close distance. The signal may include at least one ofinformation about a channel associated with the AP2 1602 or informationabout the AP2 1602.

The AP2 1602 may receive a signal sent from the AP1 1601, and generate alist of channels associated with the AP1 1601 and the AP2 1602 based onthe information included in the received signal in operation 1633.

The AP 11601 may receive a signal sent from the AP2 1602, and generate alist of channels associated with the AP1 1601 and the AP2 1602 based onthe information included in the received signal in operation 1634.

In operations 1635 and 1636, the electronic device 101 may performscanning with respect to at least one connectable AP to perform awireless communication connection.

In operation 1637, the electronic device 101 may perform the wirelesscommunication connection with one of the AP 11601 and the AP2 1602 foundas a result of the scanning.

In operation 1638, the electronic device 101 may send a request for alist of channels used to perform roaming to thewireless-communication-connected AP1 1601.

In operation 1639, the AP1 1601 may send the generated list of thechannels associated with the AP1 1601 and the AP2 1602 to the electronicdevice 101, in response to the request sent from the electronic device101.

In operation 1640, the electronic device 101 may store the list of thechannels associated with the AP1 1601 and the AP2 1602 received from theAP1 1601.

Referring to FIG. 16D, in operation 1641, the AP1 1601 may continuouslytransmit a beacon for identifying an AP located at a close distancethrough a channel 1 associated with the AP1 1601. The beacon mayinclude, for example, at least one of information about the channel 1associated with the AP1 1601 or information about the AP1 1601. Inoperation 1643, the AP2 1602 may switch to the channel 1 that is one ofavailable channels, and receive the beacon transmitted through thechannel 1 from the AP1 1601. The AP2 1602 may receive a beacon sent fromthe AP1 1601, and generate a list of channels associated with the AP11601 and the AP2 1602 based on the information included in the receivedbeacon in operation 1645.

In operation 1642, the AP2 1602 may transmit a beacon for identifying anAP located at a close distance through a channel 2 associated with theAP2 1602. The beacon may include at least one of information about thechannel 2 associated with the AP2 1602 or information about the AP21602. In operation 1644, the AP1 1601 may switch to the channel 2 thatis one of available channels, and receive the beacon transmitted throughthe channel 2 from the AP2 1602. The AP1 1601 may receive a beacon sentfrom the AP2 1602, and generate a list of channels associated with theAP1 1601 and the AP2 1602 based on the information included in thereceived beacon in operation 1646.

In operations 1647 and 1648, the electronic device 101 may performscanning with respect to at least one connectable AP to perform awireless communication connection.

In operation 1649, the electronic device 101 may perform the wirelesscommunication connection with one of the AP 11601 and the AP2 1602 foundas a result of the scanning.

In operation 1650, the electronic device 101 may send a request for alist of channels used to perform roaming to thewireless-communication-connected AP1 1601.

In operation 1651, the AP1 1601 may send the generated list of thechannels associated with the AP1 1601 and the AP2 1602 to the electronicdevice 101, in response to the request sent from the electronic device101.

In operation 1652, the electronic device 101 may store the list of thechannels associated with the AP1 1601 and the AP2 1602 received from theAP1 1601.

Referring to FIGS. 16C and 16D, when the AP1 1601wireless-communication-connected with the electronic device 101 maytransmit a self-generated channel list to the electronic device 101.

FIGS. 17A and 17B are views for describing a roaming method of anelectronic device, according to various embodiments of the presentdisclosure.

As shown in FIG. 17A, an AP1 1701 (e.g., the AP 400 of FIG. 4), an AP21702 (e.g., the AP 400 of FIG. 4), and an AP3 1703 (e.g., the AP 400 ofFIG. 4) that use identical credential information may be installed athome. It is assumed that channels associated with the AP1 1701, the AP21702, and the AP3 1703 are as shown in Table 2 and the AP1 1701 is aroot AP connected to a WAN.

TABLE 2 2.4 GHz Channel 5 GHz Channel AP1 1 48 AP2 6 100 AP3 11 149

Information about channels associated with the AP1 1701, the AP2 1702,and the AP3 1703 as shown in Table 2 may be shared among the AP1 1701,the AP2 1702, and the AP3 1703 after the AP1 1701, the AP2 1702, and theAP3 1703 are initially installed or turned on/off, or may be generatedby the AP1 1701 and then delivered to the AP2 1702 and the AP3 1703. Asshown in FIG. 17A, when the electronic device 101 (e.g., the electronicdevice 101 of FIG. 1 or the electronic device 201 of FIG. 2) comes home,the electronic device 101 may be connected to the AP1 1701. After beingconnected to the AP1 1701, the electronic device 101 may send a requestfor a channel list to the AP1 1701 that may then deliver the channellist as shown in Table 1 to the electronic device 101.

As shown in Table 17B, once moving to the second floor, the electronicdevice 101 is out of a coverage of the AP1 1701 and may perform scanningby using the channel list to perform roaming. The electronic device 101may find the AP2 1702 as an AP to which roaming is to be performed, as aresult of the scanning performed using the channel list. The electronicdevice 101 may perform a wireless communication connection with thefound AP2 1702. As such, the electronic device 101 may use the channellist when performing scanning for roaming, thereby avoiding fullscanning with respect to all available channels. Thus, data interruptioncaused by full scanning may be reduced.

FIGS. 18A and 18B are views for describing a roaming method of anelectronic device according to various embodiments of the presentdisclosure.

As shown in FIGS. 18A and 18B, a plurality of APs (e.g., the AP 400 ofFIG. 4) using identical credential information are arranged on eachfloor of a building, and the plurality of APs arranged in each layer ofthe building may be managed by each of WLCs 1811 and 1812 arranged onrespective floors. It is assumed that in the building shown in FIGS. 18Aand 18B, channels as shown in Table 3 are used.

TABLE 3 2.4 GHz Channel 5 GHz Channel Odd-numbered floor 1, 6 48, 100Even-numbered floor 3, 8 36, 112 Lobby and elevator in 11 149 each floor

When a channel as shown in Table 3 is used in the building, a list ofchannels for roaming may include a list of first channels used inodd-numbered floors of the building and a list of second channels usedin even-numbered floors of the building. In another example, informationabout channels used in a public place of the building, e.g., a lobby andan elevator on each floor may be included in both the list of the firstchannels and the list of the second channels. For example, the list ofthe first channels used in an odd-numbered floor of the building mayinclude information about the channel 1, the channel 6, the channel 48,the channel 100, the channel 11, and the channel 149. The list of thesecond channels used in an even-numbered floor of the building mayinclude information about the channel 3, the channel 8, the channel 36,the channel 112, the channel 11, and the channel 149.

For example, once the electronic device 101 (e.g., the electronic device101 of FIG. 1 or the electronic device 201 of FIG. 2) enters thebuilding, the electronic device 101 may perform in the first floor ofthe building, a wireless communication connection with at least one APamong a plurality of APs arranged on the first floor. The electronicdevice 101 may receive the list of the first channels from the connectedat least one AP.

As shown in FIG. 18A, when the electronic device 101 moves to a ninthfloor 1801, channels included in the list of the first channels are usedin the ninth floor 1801 that is an odd-numbered floor, like in the firstfloor, such that the electronic device 101 may perform scanning forroaming by using the list of the first channels.

As shown in FIG. 18B, when the electronic device 101 moves to a fourthfloor 1802 from the ninth floor 1801, channels included in the list ofthe second channels may be used in the fourth floor 1802 that is aneven-numbered floor, unlike in the first floor and the ninth floor 1801.Thus, the electronic device 101 may receive the list of the secondchannels from at least one AP arranged on a lobby of the fourth floor1802. The electronic device 101 may update the list of the firstchannels by using the list of the second channels. The electronic device101 may perform scanning for roaming by using the updated list of thefirst channels. In another example, upon receiving the list of thesecond channels, the electronic device 101 may perform scanning forroaming by using the list of the second channels without updating thelist of the first channels.

According to an embodiment of the present disclosure, even when achannel is used as shown in Table 2 in the building, the list of thechannels for roaming may be generated as one channel list. For example,the channel list may include information about the channel 1, thechannel 3, the channel 6, the channel 8, the channel 11, the channel 36,the channel 48, the channel 100, the channel 112, and the channel 149.In this case, when the electronic device 101 enters the building, theelectronic device 101 may perform in the first floor of the building, awireless communication connection with at least one of a plurality ofAPs arranged on the first floor, and receive the channel list from theat least one AP. In another example, the electronic device 101 receivesthe channel list including information about all channels used in thebuilding, and thus the electronic device 101 may not further receive orupdate the channel list even when moving to the ninth floor or thefourth floor as shown in FIGS. 18A and 18B.

FIGS. 19A and 19B are flowcharts illustrating a roaming method of anelectronic device, according to various embodiments of the presentdisclosure.

Referring to FIG. 19A, in operation 1911, an AP2 1902 (e.g., the AP 400of FIG. 4) associated with the channel 100 may transmit informationabout the channel 100 and information about the AP2 1902 to an AP3 1903(e.g., the AP 400 of FIG. 4) associated with the channel 48.

In operation 1912, an AP1 1901 (e.g., the AP 400 of FIG. 4) associatedwith the channel 149 may transmit information about the channel 149 andinformation about the AP1 1901 to the AP3 1903.

In operation 1913, the AP3 1903 may generate a channel list includinginformation about the channel 48, the channel 100, and the channel 149.

In operations 1914 and 1915, the AP3 1903 may transmit the generatedchannel list to the AP2 1901 and the AP1 1901.

In operation 1916, the electronic device (e.g., the electronic device101 of FIG. 1 or the electronic device 201 of FIG. 2) may send the proberequest through the channel 48. In operation 1917, the AP3 1903 may sendthe probe response to the electronic device 101 in response to the proberequest received through the channel 48.

In operation 1918, the electronic device 101 may send the probe requestthrough the channel 100. In operation 1919, the AP2 1902 may send theprobe response to the electronic device 101 in response to the proberequest received through the channel 100.

In operation 1920, the electronic device 101 may send the probe requestthrough the channel 149. However, it is assumed that the probe requestdoes not arrive at the AP1 1901 because the electronic device 101 is outof the coverage of the AP1 1901. Thus, the electronic device 101 may notreceive the probe response from the AP1 1901 within a designated dwelltime for the channel 149 and may not find the AP1 1901.

In operation 1921, the electronic device 101 may perform the wirelesscommunication connection with one of the AP2 1902 and the AP3 1903having sent the probe response, e.g., the AP2 1902.

In operation 1922, the electronic device 101 may send a request for alist of channels used to perform roaming to thewireless-communication-connected AP2 1902.

In operation 1923, the AP2 1902 may transmit the list of the channels tothe electronic device 101.

In operation 1924, the electronic device 101 may store the list of thechannels received from the AP2 1902.

The electronic device 101 may perform scanning by using the receivedlist of the channels to perform roaming when a condition ofcommunication with the AP2 1902 is degraded because the electronicdevice 101 becomes distant from the wireless-communication-connected AP21902 or because of other reasons.

Referring to FIG. 19B, in operation 1925, the electronic device 101 maysend the probe request through the channel 48. However, it is assumedthat the probe request does not arrive at the AP3 1903 because theelectronic device 101 is located out of the coverage of the AP3 1903 dueto movement thereof. Thus, the electronic device 101 may not receive theprobe response from the AP3 1903 within a designated dwell time for thechannel 48 and may not find the AP3 1903.

In operation 1926, the electronic device 101 may send the probe requestthrough the channel 100. In operation 1927, the electronic device 101may determine a complexity of the channel 100 and increase a designateddwell time for the channel 100 when the channel 100 is determined to bein a currently complex condition. In operation 1928, the AP2 1902 maysend the probe response in response to the probe request through thechannel 100. The electronic device 101 may receive the probe responsefrom the AP2 1902 within an increasing dwell time and may find the AP21902.

In operation 1929, the electronic device 101 may send the probe requestthrough the channel 149. In operation 1930, the AP1 1901 may transmitthe probe response in response to the probe request through the channel149.

In operation 1931, the electronic device 101 may select an AP with whicha wireless communication connection is to be performed from among thefound AP1 1901 and AP2 1902, based on a result of the scanning performedusing the list of the channels.

In operation 1932, the electronic device 101 may roam to the AP1 1901 byperforming the wireless communication connection with the selected AP 11901.

According to various embodiments of the present disclosure, anelectronic device may include a wireless communication circuit locatedinside the housing and configured to support a wireless protocol for awireless connection, at a time point, with one of a plurality of APsthat use identical first credential information, a processor locatedinside the housing and electrically connected with the wirelesscommunication circuit, and a memory located inside the housing andelectrically connected with the processor. The memory may storeinstructions that cause, when executed, the processor to wirelesslyconnect to a first AP by using the first credential information, throughthe wireless communication circuit, to receive a list of first channelsat least partially associated with at least one second AP having acoverage overlapping that of the first AP among the plurality of APs,through the wireless communication circuit, and to perform scanning withrespect to the at least one second AP that uses the first credentialinformation by using the list of the first channels, through thewireless communication circuit, in which the list of the first channelsincludes, but not all, a plurality of channels among channels availablefrom the wireless protocol.

According to various embodiments of the present disclosure, the wirelessprotocol may include a WiFi protocol.

According to various embodiments of the present disclosure, the firstcredential information may include an SSID or a password.

According to various embodiments of the present disclosure, theinstructions may cause the processor to perform scanning with respect tothe at least one second AP by using the list of the first channels,through the wireless communication circuit, when an RSSI value for thefirst AP is less than or equal to a designated first threshold value orwhen the RSSI value for the first AP exceeds the first threshold valueand is less than or equal to a designated second threshold value and aCU value for the first AP is greater than or equal to a designated thirdthreshold value.

According to various embodiments of the present disclosure, theinstructions stored in the memory may cause the processor to receive thelist of the first channels from the first AP through the wirelesscommunication circuit.

According to various embodiments of the present disclosure, theinstructions stored in the memory may cause the processor to furtherreceive a list of second channels associated with at least one third APthat does not have a coverage overlapping that of the first AP among theplurality of APs through the wireless communication circuit.

According to various embodiments of the present disclosure, the memorymay further store instructions that cause the processor to performscanning with respect to the at least one third AP that uses the firstcredential information by using the list of the second channels throughthe wireless communication circuit.

According to various embodiments of the present disclosure, the memorymay further store an instruction that causes the processor to wirelesslyconnect to one of the at least one second AP by using the firstcredential information through the wireless communication circuit afterperforming scanning with respect to the at least one second AP.

According to various embodiments of the present disclosure, the memorymay further store an instruction that causes the processor to obtain atleast one of an RSSI value or a CU value for each of the at least onesecond AP and select the AP that is to be wirelessly connected fromamong the at least one second AP, by using the at least one of the RSSIvalue or CU value for each of the at least one second AP.

According to various embodiments of the present disclosure, the memorymay further store an instruction that causes the processor to receive alist of third channels associated with at least one fourth AP having acoverage overlapping a coverage of the wirelessly-connected AP among theplurality of APs, through the wireless communication circuit and toupdate the list of the first channels by using the received list of thethird channels.

According to various embodiments of the present disclosure, the memorymay further store an instruction that causes the processor to comparethe CU value for the at least one second AP with a designated fourththreshold value, to determine at least one AP with respect to whichscanning is to be performed, among the at least one second AP, based ona result of the comparison, and to perform scanning with respect to thedetermined at least one AP.

According to various embodiments of the present disclosure, the memorymay further store an instruction that causes the processor to determinecomplexities of the first channels for the at least one second AP and toadjust a dwell time for at least one channel determined to have acomplexity that is greater than or equal to a designated fifth thresholdvalue among the first channels, based on a result of the determination.

According to various embodiments of the present disclosure, the memorymay further store an instruction that causes the processor to determinecomplexities of the first channels for the at least one second AP and toperform additional scanning for at least one channel determined to havea complexity that is greater than or equal to a designated sixth valueamong the first channels, based on a result of the determination, aftercompleting scanning for the first channels associated with the at leastone second AP.

According to various embodiments of the present disclosure, the memorymay further store an instruction that causes the processor to increase adwell time for channels associated with the at least one second AP whena number of the at least one second AP is less than or equal to adesignated value.

According to various embodiments of the present disclosure, in anon-transitory computer-readable recording medium having recordedthereon a program to be executed on a computer, the program includesexecutable instructions that cause, when executed by a processor, theprocessor to wirelessly connect to a first AP by using first credentialinformation, to receive at a time point, a list of first channels atleast partially associated with at least one second AP having a coverageoverlapping that of the first AP among the plurality of APs, and toperform scanning with respect to the at least one second AP that usesthe first credential information by using the list of the firstchannels, in which the list of the first channels includes, but not all,a plurality of channels among channels available from the wirelessprotocol.

According to various embodiments of the present disclosure, the programmay include an executable instruction that causes the processor furtherto wirelessly connect to one of the at least one second AP by using thefirst credential information.

According to various embodiments of the present disclosure, the programmay include an executable instruction that causes the processor furtherto receive a list of third channels associated with at least one fourthAP having a coverage overlapping that of the wirelessly-connected APamong the plurality of APs and to update the list of the first channelsby using the received list of the third channels.

According to various embodiments of the present disclosure, the programmay include an executable instruction that causes the processor furtherto determine the complexities of the first channels associated with theat least one second AP and to adjust a dwell time for at least onechannel determined to have a complexity that is greater than or equal toa designated seventh threshold value among the first channels, based ona result of the determination.

According to various embodiments of the present disclosure, anelectronic device includes a housing and a wireless communicationcircuit located inside the housing and configured to support a wirelessprotocol as a first AP, in which the wireless communication circuit isconfigured to store a list of first channels associated with at leastone other AP having a coverage overlapping that of the first AP, thelist of the first channels including, but not all, a plurality ofchannels among channels available from the wireless protocol, towirelessly connect to an external electronic device as the first AP byusing first credential information, and to provide the list of the firstchannels to the external electronic device.

According to various embodiments of the present disclosure, the wirelesscommunication circuit may be configured to store a list of secondchannels associated with at least one other AP that does not have acoverage overlapping that of the first AP and to further provide thelist of the second channels to the external electronic device.

Each of the foregoing elements described herein may be configured withone or more components, names of which may vary with a type of theelectronic device. In various embodiments, the electronic device mayinclude at least one of the foregoing elements, some of which may beomitted or to which other elements may be added. In addition, some ofthe elements of the electronic device according to various embodimentsmay be integrated into one entity to perform functions of thecorresponding elements in the same manner as before they are integrated.

A term “module” used herein may mean, for example, a unit including oneof or a combination of two or more of hardware, software, and firmware,and may be used interchangeably with terms such as logic, a logic block,a part, or a circuit. The “module” may be a part configured integrally,a minimum unit or a portion thereof performing one or more functions.The “module” may be implemented mechanically or electronically, and mayinclude an application-specific integrated circuit (ASIC) chip,field-programmable gate arrays (FPGAs), and a programmable-logic deviceperforming certain operations already known or to be developed.

At least a part of an apparatus (e.g., modules or functions thereof) ora method (e.g., operations) according to various embodiments may beimplemented with an instruction stored in a computer-readable storagemedium (e.g., the memory 130) in the form of a programming module. Whenthe instructions are executed by a processor (for example, the processor120), the processor may perform functions corresponding to theinstructions.

The computer-readable recording medium includes hard disk, floppy disk,or magnetic media (e.g., a magnetic tape, optical media (e.g., compactdisc read only memory (CD-ROM) or digital versatile disc (DVD),magneto-optical media (e.g., floptical disk), an embedded memory, and soforth. The instructions may include a code generated by a compiler or acode executable by an interpreter. Modules or programming modulesaccording to various embodiments of the present disclosure may includeone or more of the foregoing elements, have some of the foregoingelements omitted, or further include additional other elements.Operations performed by the module, the program, or another componentaccording to various embodiments may be carried out sequentially, inparallel, repeatedly, or heuristically, or one or more of the operationsmay be executed in a different order or omitted, or one or more otheroperations may be added.

According to various embodiments of the present disclosure, in anon-transitory computer-readable recording medium having recordedthereon a program to be executed on a computer, the program includesexecutable instructions that cause, when executed by a processor, theprocessor to wirelessly connect to a first AP by using first credentialinformation, to receive at a time point, a list of first channels atleast partially associated with at least one second AP having a coverageoverlapping that of the first AP among the plurality of APs, and toperform scanning with respect to the at least one second AP that usesthe first credential information by using the list of the firstchannels, in which the list of the first channels includes, but not all,a plurality of channels among channels available from the wirelessprotocol.

The embodiments disclosed herein have been provided for description andunderstanding of disclosed technical matters, and are not intended tolimit the scope of the present disclosure. Therefore, it should beconstrued that the scope of the present disclosure includes any changeor other various embodiments based on the technical spirit of thepresent disclosure.

The invention claimed is:
 1. An electronic device comprising: a housing;a wireless communication circuit located inside the housing andconfigured to support a wireless protocol for a wireless connection, ata time point, with one of a plurality of access points (APs) that useidentical first credential information, wherein the wireless protocolcomprises a Wireless Fidelity (WiFi) protocol and the first credentialinformation comprises a service set identifier (SSID); a processorlocated inside the housing and electrically connected with the wirelesscommunication circuit; and a memory located inside the housing andelectrically connected with the processor, wherein the memory storesinstructions that are configured to cause, when executed, the processorto: wirelessly connect to a first AP by using the first credentialinformation, through the wireless communication circuit; receive, fromthe first AP, a list of first channels at least partially associatedwith at least one second AP having a coverage overlapping a coverage ofthe first AP and a list of second channels associated with at least onethird AP that does not have a coverage overlapping the coverage of thefirst AP through the wireless communication circuit, wherein the firstAP, the at least one second AP, and the at least one third AP use theidentical first credential information; increase a dwell time for eachof the first channels at least partially associated with the at leastone second AP, if a number of the at least one second AP is less than orequal to a designated value; and based on the increased dwell time foreach of the first channels, perform scanning with respect to the atleast one second AP by using the list of the first channels, through thewireless communication circuit, wherein the list of the first channelscomprises, but not all, a plurality of channels among channels availablefrom the wireless protocol.
 2. The electronic device of claim 1, whereinthe instructions are configured to cause the processor to performscanning with respect to the at least one second AP by using the list ofthe first channels, through the wireless communication circuit, when areceived signal strength indication (RSSI) value for the first AP isless than or equal to a designated first threshold value or when theRSSI value for the first AP exceeds the first threshold value and isless than or equal to a designated second threshold value and a channelutilization (CU) value for the first AP is greater than or equal to adesignated third threshold value.
 3. The electronic device of claim 1,wherein the memory further stores instructions that are configured tocause the processor to perform scanning with respect to the at least onethird AP by using the list of the second channels, through the wirelesscommunication circuit.
 4. The electronic device of claim 1, wherein thememory further stores instructions that are configured to cause theprocessor to wirelessly connect to one of the at least one second AP byusing the first credential information through the wirelesscommunication circuit, after performing scanning with respect to the atleast one second AP.
 5. The electronic device of claim 4, wherein thememory further stores instructions that are configured to cause theprocessor to: obtain at least one of an RSSI value or a CU value foreach of the at least one second AP; and select an AP that is to bewirelessly connected from among the at least one second AP, by using theat least one of the RSSI value or CU value for each of the at least onesecond AP.
 6. The electronic device of claim 4, wherein the memoryfurther stores instructions that are configured to cause the processorto: receive a list of third channels associated with at least one fourthAP having a coverage overlapping a coverage of the wirelessly connectedAP among the plurality of APs, through the wireless communicationcircuit; and update the list of the first channels by using the receivedlist of the third channels.
 7. The electronic device of claim 1, whereinthe memory further stores instructions that are configured to cause theprocessor to: compare a CU value for the at least one second AP with adesignated fourth threshold value; determine at least one AP withrespect to which scanning is to be performed, among the at least onesecond AP, based on a result of the comparison; and perform scanningwith respect to the determined at least one AP.
 8. The electronic deviceof claim 1, wherein the memory further stores instructions that areconfigured to cause the processor to: determine levels of channelutilization of the first channels at least partially associated with theat least one second AP; and adjust a dwell time for at least one channeldetermined to have a level of channel utilization that is greater thanor equal to a designated fifth threshold value among the first channels,based on a result of the determination.
 9. The electronic device ofclaim 1, wherein the memory further stores instructions that areconfigured to cause the processor to: determine levels of channelutilization of the first channels at least partially associated with theat least one second AP; and perform additional scanning for at least onechannel determined to have a level of channel utilization that isgreater than or equal to a designated sixth value among the firstchannels, based on a result of the determination, after completingscanning for the first channels at least partially associated with theat least one second AP.
 10. A non-transitory computer-readable recordingmedium including recorded thereon a program to be executed on acomputer, wherein the program comprises executable instructions that areconfigured to cause, when executed by a processor, the processor to:wirelessly connect to a first access point (AP) by using firstcredential information, through a wireless communication circuitelectrically connected with the processor and configured to support awireless protocol for a wireless connection with one of a plurality ofaccess points (APs); receive, from the first AP, at a time point, a listof first channels at least partially associated with at least one secondAP having a coverage overlapping a coverage of the first AP and a listof second channels associated with at least one third AP that does nothave a coverage overlapping the coverage of the first AP, through thewireless communication circuit, wherein the first AP, the at least onesecond AP, and the at least one third AP use identical first credentialinformation; increase a dwell time for each of the first channels atleast partially associated with the at least one second AP, if a numberof the at least one second AP is less than or equal to a designatedvalue; and based on the increased dwell time for each of the firstchannels, perform scanning with respect to the at least one second AP byusing the list of the first channels, wherein the list of the firstchannels comprises, but not all, a plurality of channels among channelsavailable from the wireless protocol, wherein the wireless protocolcomprises a Wireless Fidelity (WiFi) protocol and the first credentialinformation comprises a service set identifier (SSID).
 11. Thenon-transitory computer-readable recording medium of claim 10, whereinthe program comprises executable instructions that are configured tocause the processor further to wirelessly connect to one of the at leastone second AP by using the first credential information.
 12. Thenon-transitory computer-readable recording medium of claim 11, whereinthe program comprises executable instructions that are configured tocause the processor further to: receive a list of third channelsassociated with at least one fourth AP having a coverage overlapping acoverage of the wirelessly connected AP among the plurality of APs; andupdate the list of the first channels by using the received list of thethird channels.
 13. The non-transitory computer-readable recordingmedium of claim 10, wherein the program comprises executableinstructions that are configured to cause the processor further to:determine levels of channel utilization of the first channels at leastpartially associated with the at least one second AP; and adjust a dwelltime for at least one channel determined to have a level of channelutilization that is greater than or equal to a designated sevenththreshold value among the first channels, based on a result of thedetermination.